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Kenjiro Terada

Section

Graduate School of Engineering

Job title

Professor

Degree

Ｐｈ．Ｄ．（ミシガン大学）

researchmap

https://researchmap.jp/teinoji0705

J-GLOBAL ID

200901009129530842

Research History 5

2024/04 - Present

Tohoku University　Graduate School of Engineering, Department of Civil and Environmental Engineering　Professor
2012/07 - 2024/03

International Research Institute of Disaster Science, Tohoku University　Professor
1999/07 - 2012/06

Department of Civil Engineering, Graduate School of Engineering, Tohoku University　Associate Professor
1997/05 - 1999/06

Graduate School of Information Science, Tohoku University　Assistant Professor
1996/04 - 1997/04

Department of Naval Architecture and Ocean Engineering., Faculty of Engineering, The University of Tokyo　Research Associate

Education 2

The University of Michigan　Dept. of Mech. Engineering and Applied Mech.　Applied Mechanics

- 1996/03/31
Nagoya University　Faculty of Engineering　土木工学

- 1990/03/31

Professional Memberships 8

International Association for Computational Mechanics

1996/08 - Present
Japan Society of Civil Engineers

1995/04 - Present
Japan Association for Nonlinear CAE

2003/05 -
The Iron and Steel Institute of Japan

2003/04 -
Japanese Geotechnical Society

1997/04 -
The Japan Society for Computational Engineering and Science

1996/04 -
The Japan Society of Mechanical Engineers

1995/04 -
材料学会

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Research Interests 4

Solid Mechanics
Applied Mechanics
Computer-Aided Engineering
Computational Mechanics

Research Areas 3

Social infrastructure (civil Engineering, architecture, disaster prevention) / Structural and seismic engineering / Applied Mechanics
Social infrastructure (civil Engineering, architecture, disaster prevention) / Civil engineering (materials, implementation, construction management) / Computational Mechanics
Informatics / Computational science / Computational Mechanics

Awards 11

Paper Award

2020/05　The Japan Society for Computational Engineering and Sciences
Achievement Award

2020/05　The Japan Society for Computational Engineering and Sciences
JSME Paper Award

2018/05　The Japan Society of Mechanical Engineers
Outstanding Paper: Awards for Excellence

2018　Emerald Publishing　Numerical simulations of non-stationary distributions of electrochemical potentials in SOFC
The IACM Fellows Award

2014/07　International Association for Computational Mechanics
Paper Award

2014/05　The Japan Society for Computational Engineering and Sciences
The Kawai Medal

2014/05　The Japan Society for Computational Engineering and Sciences
Paper Award

2013/05　The Japan Society for Computational Engineering and Sciences
日本機械学会・計算力学部門業績賞

2007/11　日本機械学会・計算力学部門　計算力学部門における業績が認められた
計算工学会論文賞

2007/05　日本計算工学会　日本計算工学会論文集に投稿された論文「多重被覆モデリングによる有限被覆法－非均質脆性材料の不連続面進展解析－」日本計算工学会論文賞に値すると認められた
日本計算工学会論文賞

2003/05/19　日本計算工学会　日本計算工学会論文集に掲載された論文「Kinematically correct formulation for two-scale finite deformation problems, Transaction of JSCES, Vol. 2, 53-62, 2000」が日本計算工学会論文賞に値すると認められた

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Papers 415

Surrogate Computational Homogenization of Viscoelastic Composites

Yosuke Yamanaka, Norio Hirayama, Kenjiro Terada

International Journal for Numerical Methods in Engineering　126　(6)　2025/03/18
Publisher: Wiley
DOI： 10.1002/nme.70008 　

ISSN： 0029-5981

eISSN： 1097-0207

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ABSTRACT We establish a surrogate model for computational homogenization of composite materials consisting of multiple viscoelastic constituents. A surrogate macroscopic material is identified by performing interpolation using radial basis functions (RBFs) and cubic spline functions on a constitutive database generated by a series of microscopic analyses or, equivalently, numerical material tests (NMTs) on a unit cell to represent anisotropic stress relaxation behavior as well as its dependence on strain rate and temperature. After briefly reviewing the two‐scale boundary value problem derived based on homogenization theory, an RBF interpolation with a normalized kernel is formulated for a discrete dataset, and an optimization algorithm is applied to determine the three hyperparameters so as to achieve proper interpolation. Then, we formulate the surrogate homogenization model (SHM) using the interpolants to substitute for the macroscopic viscoelastic response. To show the specific procedure of the proposed surrogate modeling and demonstrate the performance of the created SHM, a representative numerical example is presented in the offline and online stages. In the offline stage, NMTs are carried out in the space of training data, including the temperature, to generate a dataset as long as the macroscopic stresses can be learned exhaustively, and then optimization is performed to determine the set of hyperparameters. Then, to validate the created SHM, its responses to unseen loading and temperature histories are compared with the corresponding NMT results. In the online stage, the created SHM is used to carry out a macroscopic analysis of a simple structure under specific loading and temperature conditions, and subsequently, the obtained macroscopic stresses are compared with those obtained from the localization analysis results. The results are also compared with those obtained from the single‐scale direct numerical analyses.
A novel design update framework for topology optimization with quantum annealing: Application to truss and continuum structures

Naruethep Sukulthanasorn, Junsen Xiao, Koya Wagatsuma, Reika Nomura, Shuji Moriguchi, Kenjiro Terada

Computer Methods in Applied Mechanics and Engineering　437　117746-117746　2025/03
Publisher: Elsevier BV
DOI： 10.1016/j.cma.2025.117746 　

ISSN： 0045-7825
Radial basis function-based surrogate computational homogenization for elastoplastic composites at finite strain

Akari Nakamura, Yosuke Yamanaka, Reika Nomura, Shuji Moriguchi, Kenjiro Terada

Computer Methods in Applied Mechanics and Engineering　436　117708-117708　2025/03
Publisher: Elsevier BV
DOI： 10.1016/j.cma.2024.117708 　

ISSN： 0045-7825
Topology optimization for nonlocal elastoplasticity at finite strain

Jike Han, Kozo Furuta, Tsuguo Kondoh, Kazuhiro Izui, Shinji Nishiwaki, Kenjiro Terada

Computer Methods in Applied Mechanics and Engineering　435　117678-117678　2025/02
Publisher: Elsevier BV
DOI： 10.1016/j.cma.2024.117678 　

ISSN： 0045-7825
EFFECTS OF INERTIAL FORCE TERM ON THE 2D SHALLOW WATER FLOW THROUGH COASTAL FORESTS

ISHIZAWA Shuji, NOMURA Reika, MORIGUCHI Shuji, TERADA Kenjiro

Japanese Journal of JSCE　81　(15)　n/a　2025
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejj.24-15006 　

eISSN： 2436-6021

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This study investigates the inﬂuence of the inertial force term in shallow water simulations through a coastal forest. First, we formulate two patterns of 2D shallow water momentum equation which consider trees’ resistance as an external force term consisting of either the drag force or the combination of drag and inertial forces. To obtain the parameters characterizing drag and inertial force, we carry out the 3D numerical ﬂow tests with the 3D tree model. Finally, we conduct several 2D dam break simulations by incorporating the evaluated parameters into the resistance force term. By comparing the wave arrival time and the inundation depth, we could argue that the existence of inertial force has the potential to aﬀect the ultimate evaluation of disaster mitigation performance of trees if they are densely arranged.
Comparative Performance of Scenario Superposition by Sequential Bayesian Update for Tsunami Risk Evaluation

Nomura Reika, Hirao-Vermare Louise Ayako, Fujita Saneiki, Rim Donsub, Moriguchi Shuji, LeVeque Randall J., Terada Kenjiro

Journal of Disaster Research　19　(6)　896-911　2024/12/01
Publisher: Fuji Technology Press Ltd.
DOI： 10.20965/jdr.2024.p0896 　

ISSN： 1881-2473

eISSN： 1883-8030

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This study aims to evaluate the performance of the previous sequential Bayesian update for synthesizing tsunami scenarios in a diverse database consisting of complex fault rupture patterns with heterogeneous slip distributions. We utilize an existing database comprising 1771 tsunami scenarios targeting the city of Westport (WA, U.S.), which includes synthetic wave height records and inundation distributions resulting from a fault rupture in the Cascadia subduction zone. After preprocessing the training dataset according to the developed framework, Bayesian updates are performed sequentially to evaluate the probability that each training scenario is a test case. In addition to detecting the scenario with the highest probability, i.e., the most likely scenario, we synthesize the scenario by the weighted mean of all the learning scenarios by their probabilities. The accuracies of tsunami risk evaluation based on both resultant scenarios are evaluated from the maximum offshore wave, inundation depth, and its distribution. The results of the cross-validation with five different testing/training datasets showed that the weighted mean scenario has almost comparable performance to that of the most likely scenario. Additionally, the sequential Bayesian update improves the accuracy of both methods if a 3–4 minute observation time window is given, and has an advantage over the benchmark results provided by dynamic time warping with full-time series data.
Scenario Superposition Method for Real‐Time Tsunami Prediction Using a Bayesian Approach

Saneiki Fujita, Reika Nomura, Shuji Moriguchi, Yu Otake, Randall J. LeVeque, Kenjiro Terada

Journal of Geophysical Research: Oceans　129　(12)　2024/12
Publisher: American Geophysical Union (AGU)
DOI： 10.1029/2024jc021565 　

ISSN： 2169-9275

eISSN： 2169-9291

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Abstract In this study, we propose a scenario superposition method for real‐time tsunami wave prediction. In the offline phase, prior to actual tsunami occurrence, hypothetical tsunami scenarios are created, and their wave data are decomposed into spatial modes and scenario‐specific coefficients by the singular value decomposition. Then, once an actual tsunami event is observed, the proposed method executes an online phase, which is a novel contribution of this study. Specifically, the predicted waveform is represented by a linear combination of training scenarios consisting of precomputed tsunami simulation results. To make such a prediction, a set of weight parameters that allow for appropriate scenario superposition is identified by the Bayesian update process. At the same time, the probability distribution of the weight parameters is obtained as reference information regarding the reliability of the prediction. Then, the waveforms are predicted by superposition with the estimated weight parameters multiplied by the waveforms of the corresponding scenarios. To validate the performance and benefits of the proposed method, a series of synthetic experiments are performed for the Shikoku coastal region of Japan with the subduction zone of the Nankai Trough. All tsunami data are derived from numerical simulations and divided into a training data set used as scenario superposition components and a test data set for an unknown real event. The predicted waveforms at the synthetic gauges closest to the Shikoku Islands are compared to those obtained using our previous prediction method incorporating sequential Bayesian updating.
Status and Challenges of Convergence Knowledge in Disaster Science: A Qualitative Analysis of Researchers’ Responses at Tohoku University

Natsuko Chubachi, Kenjiro Terada, Shunichi Koshimura, Shinichi Egawa

Journal of Disaster Research　19　(6)　943-955　2024/12/01
Publisher: Fuji Technology Press Ltd.
DOI： 10.20965/jdr.2024.p0943 　

ISSN： 1881-2473

eISSN： 1883-8030

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Researchers with different academic backgrounds work together in disaster science. This qualitative study explores similarities and differences in the perceptions of values and measures of research outcomes in disaster science’s sub-disciplines. We also investigate how researchers trained initially in different study areas communicate, reflecting the state of Convergence Knowledge in disaster science. In this paper, 37 disaster science researchers in the sciences and humanities responded to an open-ended questionnaire survey. Regardless of their specialties, they evaluated an academic paper based on three main criteria: the researchers’ perception of the paper, the medium in which the paper was published, and the way it was used and read. They tended to value originality and the capacity to meet social needs. They pointed out matters in disaster science that should be acknowledged and the need for new indicators to assess them properly. However, attitudes toward numerical metrics and publication frequency differed by discipline. Also, there are few standard disaster science journals where they publish their successful papers, and the number of peers with whom they can interact professionally is limited. Therefore, the scope of academic understanding among disaster science researchers is limited, and its Convergence Knowledge has not yet been systematically advanced. However, mutual differences and the significance of interdisciplinary collaboration are recognized. Clarifying the benefits of interdisciplinary studies for researchers and launching appropriate indicators through cooperation among diverse sub-disciplines may advance Convergence Knowledge.
Topology optimization with a finite strain nonlocal damage model using the continuous adjoint method

Jike Han, Kozo Furuta, Tsuguo Kondoh, Kazuhiro Izui, Shinji Nishiwaki, Kenjiro Terada

Computer Methods in Applied Mechanics and Engineering　432　117333-117333　2024/12
Publisher: Elsevier BV
DOI： 10.1016/j.cma.2024.117333 　

ISSN： 0045-7825
Surrogate modeling for transient electrochemical potential analysis for SOFC using proper orthogonal decomposition

Masami Sato, Mayu Muramatsu, Kenta Tozato, Shuji Moriguchi, Tatsuya Kawada, Kenjiro Terada

Solid State Ionics　414　2024/10

DOI： 10.1016/j.ssi.2024.116642 　

ISSN： 0167-2738
Topology optimization of finite strain elastoplastic materials using continuous adjoint method: Formulation, implementation, and applications

Jike Han, Kozo Furuta, Tsuguo Kondoh, Shinji Nishiwaki, Kenjiro Terada

Computer Methods in Applied Mechanics and Engineering　429　117181-117181　2024/09
Publisher: Elsevier BV
DOI： 10.1016/j.cma.2024.117181 　

ISSN： 0045-7825
Linking affected community and academic knowledge: a community-based participatory research framework based on a Shichigahama project Peer-reviewed

Shuji Seto, Junko Okuyama, Toshiki Iwasaki, Yu Fukuda, Toru Matsuzawa, Kiyoshi Ito, Hiroki Takakura, Kenjiro Terada, Fumihiko Imamura

Scientific Reports　14　(1)　2024/08/28
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/s41598-024-70813-9 　

eISSN： 2045-2322
A diffusive‐discrete crack transition scheme for ductile fracture at finite strain

Jike Han, Yuichi Shintaku, Shuji Moriguchi, Kenjiro Terada

International Journal for Numerical Methods in Engineering　2024/06/27
Publisher: Wiley
DOI： 10.1002/nme.7553 　

ISSN： 0029-5981

eISSN： 1097-0207

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Summary This study presents a diffusive‐discrete crack transition scheme for stably conducting ductile fracture simulations within a finite strain framework. In the developed scheme, the crack initiation and propagation processes are determined according to an energy minimization problem based on crack phase‐field theory, and the predicted diffusive path is transformed to a discrete representation using the finite cover method during the staggered iterative scheme. In particular, for stably conducting ductile fracture simulations, three computational techniques, the staggered iterative configuration update technique, the subincremental damage update technique, and the crack opening stabilization technique, are introduced. The first and second techniques can be used regardless of whether discrete cracks are considered, and the third technique is specialized for diffusive‐discrete crack transition schemes. Accordingly, ductile fracture simulations with the developed scheme rarely encounter troublesome problems such as oscillations in the displacement field and severe distortion of finite elements that can lead to divergence of calculations. After the crack phase‐field model for ductile fractures is formulated and discretized, the numerical algorithms for realizing the diffusive‐discrete crack transition while maintaining computational stability are explained. Several representative numerical examples are presented to demonstrate the performance and capabilities of the developed approach.
Diffusive-discrete crack transition without remeshing achieved by extended B-spline-based implicit material point method

Riichi Sugai, Jike Han, Shuji Moriguchi, Kenjiro Terada

Computer Methods in Applied Mechanics and Engineering　421　2024/03/01

DOI： 10.1016/j.cma.2024.116771 　

ISSN： 0045-7825
Optimization of a Tsunami Gauge Configuration for Pseudo-Super-Resolution of Wave Height Distribution

Saneiki Fujita, Reika Nomura, Shuji Moriguchi, Yu Otake, Shunichi Koshimura, Randall J. LeVeque, Kenjiro Terada

Earth and Space Science　11　(2)　2024/02

DOI： 10.1029/2023EA003144 　

eISSN： 2333-5084
Crack phase-field enhanced finite cover method for dynamic fracture at finite strain

Jike Han, Daigo Hirayama, Yuichi Shintaku, Shuji Moriguchi, Kenjiro Terada

International Journal for Numerical Methods in Engineering　125　(2)　2024/01/30

DOI： 10.1002/nme.7371 　

ISSN： 0029-5981

eISSN： 1097-0207
Sensitivity analysis on critical combinations of input parameters in DEM granular flow analysis

Junsen Xiao, Kenta Tozato, Reika Nomura, Yu Otake, Kenjiro Terada, Shuji Moriguchi

Acta Geotechnica　2024

DOI： 10.1007/s11440-024-02499-2 　

ISSN： 1861-1125

eISSN： 1861-1133
A Study on Digital Model for Decision-Making in Crisis Response

Naoko Kosaka, Shuji Moriguchi, Akihiro Shibayama, Tsuneko Kura, Naoko Shigematsu, Kazuki Okumura, Erick Mas, Makoto Okumura, Shunichi Koshimura, Kenjiro Terada, Akinori Fujino, Hiroshi Matsubara, Masaki Hisada

Journal of Disaster Research　19　(3)　489-500　2024

DOI： 10.20965/jdr.2024.p0489 　

ISSN： 1881-2473

eISSN： 1883-8030
A numerical simulation method combining gradient damage model and finite cover method for dynamic fracture

Daigo Hirayama, Jike Han, Shuji Moriguchi, Kenjiro Terada

Transactions of the Japan Society for Computational Engineering and Science　2024　2024

DOI： 10.11421/jsces.2024.20240001 　

eISSN： 1347-8826
Quantification of the contribution ratio of relevant input parameters on DEM-based granular flow simulations

Junsen Xiao, Kenta Tozato, Shuji Moriguchi, Yu Otake, Kenjiro Terada

Soils and Foundations　63　(6)　2023/12

DOI： 10.1016/j.sandf.2023.101378 　

ISSN： 0038-0806
Surrogate modeling for the homogenization of elastoplastic composites based on RBF interpolation

Yosuke Yamanaka, Seishiro Matsubara, Norio Hirayama, Shuji Moriguchi, Kenjiro Terada

Computer Methods in Applied Mechanics and Engineering　415　2023/10/01

DOI： 10.1016/j.cma.2023.116282 　

ISSN： 0045-7825
Hydrologic-geotechnical modelling of shallow landslide and flood hazards caused by heavy rainfall

Nilo Lemuel J. Dolojan, Shuji Moriguchi, Masakazu Hashimoto, Nguyen Xuan Tinh, Hitoshi Tanaka, Kenjiro Terada

Engineering Geology　323　107184-107184　2023/09
Publisher: Elsevier BV
DOI： 10.1016/j.enggeo.2023.107184 　

ISSN： 0013-7952
Variable passing method for combining 3D MPM-FEM hybrid and 2D shallow water simulations of landslide-induced tsunamis

Shaoyuan Pan, Reika Nomura, Guoming Ling, Shinsuke Takase, Shuji Moriguchi, Kenjiro Terada

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS　2023/08

DOI： 10.1002/fld.5233 　

ISSN： 0271-2091

eISSN： 1097-0363
Local Mechanical Characterization and Fracture Prediction Modeling for Resistance Spot-Welded Joints of Advanced High-Strength Steel

Zhenduo Yao, Masaki Omiya, Ninshu Ma, Shinnosuke Nishi, Kenji Takada, Kazuaki Okato, Kai Oide, Takaya Kobayashi, Jike Han, Kenjiro Terada

Materials Today Communications　106787-106787　2023/08
Publisher: Elsevier BV
DOI： 10.1016/j.mtcomm.2023.106787 　

ISSN： 2352-4928
Decision-making support utilizing real-time tsunami inundation and damage forecast Peer-reviewed

Naoko Kosaka, Shunichi Koshimura, Kenjiro Terada, Yoichi Murashima, Tsuneko Kura, Akira Koyama, Hiroshi Matsubara

International Journal of Disaster Risk Reduction　94　103807-103807　2023/08
Publisher: Elsevier BV
DOI： 10.1016/j.ijdrr.2023.103807 　

ISSN： 2212-4209
(High-Temperature Energy, Materials, & Processes Division Subhash Singhal Award) From Electrochemical to Mechanical Modeling of SOFCs and Their Experimental Validation

Tatsuya Kawada, Satoshi Watanabe, Riyan Achmad Budiman, Keiji Yashiro, Kazuhisa Sato, Toshiyuki Hashida, Yuta Kimura, Takashi Nakamura, Koji Amezawa, Masami Sato, Reika Nomura, Mayu Muramatsu, Kenjiro Terada

ECS Transactions　111　(6)　35-46　2023/05/19
Publisher: The Electrochemical Society
DOI： 10.1149/11106.0035ecst 　

ISSN： 1938-5862

eISSN： 1938-6737

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Tohoku University has been conducting research on the mechanical reliability of SOFCs under the financial support by NEDO (New Energy and Industrial technology Development Organization, Japan). Both numerical and experimental approaches have been taken at various levels, from electrochemical to structural analyses. An in-house code, SIMUDEL, was developed to simulate oxygen potential distribution inside the constituent materials in order to account for the chemical strain in cell/stack analyses. Non-linear stress-strain behaviors and inelastic deformation of the materials were characterized to improve the accuracy of the simulation. Predicting actual cell behavior, however, is still difficult, as unexpected factors often remain for each specific case. It is thus important to have in-situ or operando tools to observe the behavior of cells, such as deformation and stress generation. For that purpose, laser profilometer and X-ray stress analyzer were employed with a specially designed cell holder. Methods for evaluating local current density was also proposed. Currently, we are developing a protocol for testing robustness of planar SOFCs. Severe condition tests will be performed, and the results will be analyzed with the above-mentioned simulation.
A method of fully implicit coupled analyses for thermoset resin subjected to cure based on variationally consistent formulation for finite thermo-viscoelasticity

Yosuke Yamanaka, Seishiro Matsubara, Shuji Moriguchi, Kenjiro Terada

International Journal of Solids and Structures　268　112161-112161　2023/04
Publisher: Elsevier BV
DOI： 10.1016/j.ijsolstr.2023.112161 　

ISSN： 0020-7683
A method for rockfall risk quantification and optimal arrangement of protection structures along a road

Hasuka Kanno, Shuji Moriguchi, Yuto Tsuda, Ikumasa Yoshida, Shoji Iwanaga, Kenjiro Terada

Engineering Geology　314　2023/03/05

DOI： 10.1016/j.enggeo.2023.107004 　

ISSN： 0013-7952
Extended B‐spline‐based implicit material point method enhanced by F‐bar projection method to suppress pressure oscillation

Riichi Sugai, Jike Han, Yuya Yamaguchi, Shuji Moriguchi, Kenjiro Terada

International Journal for Numerical Methods in Engineering　124　(11)　2423-2448　2023/02/12
Publisher: Wiley
DOI： 10.1002/nme.7216 　

ISSN： 0029-5981

eISSN： 1097-0207
Surrogate Model-based Multiscale Analysis of Elastoplastic Composites with Nonperiodicity

Akari Nakamura, Yosuke Yamanaka, Yuichi Shintaku, Norio Hirayama, Shuji Moriguchi, Kenjiro Terada

Transactions of the Japan Society for Computational Engineering and Science　2023　2023

DOI： 10.11421/jsces.2023.20230008 　

eISSN： 1347-8826
Gradient damage model for ductile fracture introducing degradation of damage hardening modulus: implementation and experimental investigations

Jike Han, Seishiro Matsubara, Shinnosuke Nishi, Kenji Takada, Mayu Muramatsu, Masaki Omiya, Kensuke Ogawa, Kai Oide, Takaya Kobayashi, Masanobu Murata, Shuji Moriguchi, Kenjiro Terada

International Journal of Fracture　240　(2)　183-208　2022/12/06
Publisher: Springer Science and Business Media LLC
DOI： 10.1007/s10704-022-00681-9 　

ISSN： 0376-9429

eISSN： 1573-2673

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Abstract This study presents a gradient damage model for ductile fracture, in which the damage hardening modulus is degraded by the accumulation of plastic deformation and the volume expansion caused by negative hydrostatic pressure. The proposed model fulfills the thermodynamic requirements, and the governing equations are derived from energy minimization principles. Two parameter studies are carried out to confirm the basic performance of the proposed model, in which some typical ductile fracture responses are demonstrated by changing parameters for degrading the damage hardening modulus. Also, a series of numerical experiments are presented to reveal the ability of the proposed model to successfully simulate the fracture tests of advanced high strength steel sheets with different tensile strengths. It is indeed confirmed by the close agreement with experimental results that the proposed model is capable of realizing the breaking elongation, the transitional behavior from unstable to stable crack propagations, and the corresponding load–displacement curves. Also, the model successfully reproduces and predicts the crack initiation positions in notched specimens with different notch radii.
A numerical study on the effects of particle size distribution on run-out distance of granular flow

D. Watanabe, S. Moriguchi, K. Terada

Soils and Foundations　62　(6)　101242-101242　2022/12
Publisher: Elsevier BV
DOI： 10.1016/j.sandf.2022.101242 　

ISSN： 0038-0806
A transition scheme from diffusive to discrete crack topologies at finite strain during the course of a staggered iterative procedure

Jike Han, Yuichi Shintaku, Shuji Moriguchi, Kenjiro Terada

International Journal for Numerical Methods in Engineering　124　(6)　1405-1433　2022/11/21
Publisher: Wiley
DOI： 10.1002/nme.7169 　

ISSN： 0029-5981

eISSN： 1097-0207
On the flow conditions requiring detailed geometric modeling for multiscale evaluation of coastal forests

Reika Nomura, Shinsuke Takase, Shuji Moriguchi, Kenjiro Terada

2022/10/12
Publisher: Research Square Platform LLC
DOI： 10.21203/rs.3.rs-2056280/v1 　

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Abstract The multiscale evaluation method is applied to assess the influence of detailed geometric modeling of trees on their macroscopic attenuation effect against tsunami-like flow. Specifically, we conduct a series of numerical flow tests (NFTs), i.e., 3D flow simulations in a local test domain (LTD), under various inflow conditions to evaluate the macroscopic flow characteristics in the LTD accommodating an array of either simple cylinder or detailed tree models that mimic a coastal forest. After the procedure of NFTs in the multiscale evaluation method is briefly summarized and the corresponding governing equations and analysis conditions are presented, we introduce two indices for evaluating the macroscopic flow characteristics within the framework of multiscale modeling. Based on the NFT results, we discuss how the modeling scheme for trees influences the macroscopic flow characteristics in terms of these indices and clarify the microscopic mechanisms that influence the macroscopic attenuation property. Additionally, the NFT results are compared with the experimental results to justify these discussions, and key factors are explored in terms of reproducing real phenomena. In addition, to apply the multiscale evaluation method to assess the disaster mitigation performance of various types of ecosystems in a realistic situation, we discuss under what circumstances and with what level of detail vegetation should be modeled.
Sequential Bayesian Update to Detect the Most Likely Tsunami Scenario Using Observational Wave Sequences Peer-reviewed

Reika Nomura, Saneiki Fujita, Joseph M. Galbreath, Yu Otake, Shuji Moriguchi, Shunichi Koshimura, Randall J. LeVeque, Kenjiro Terada

Journal of Geophysical Research: Oceans　127　(10)　2022/10/05
Publisher: American Geophysical Union (AGU)
DOI： 10.1029/2021jc018324 　

ISSN： 2169-9275

eISSN： 2169-9291
Variational crack phase-field model for ductile fracture with elastic and plastic damage variables

Jike Han, Seishiro Matsubara, Shuji Moriguchi, Kenjiro Terada

Computer Methods in Applied Mechanics and Engineering　400　115577-115577　2022/10
Publisher: Elsevier BV
DOI： 10.1016/j.cma.2022.115577 　

ISSN： 0045-7825
Limit equilibrium method-based 3D slope stability analysis for wide area considering influence of rainfall

Kenta Tozato, Nilo Lemuel J. Dolojan, Yoshiya Touge, Shuichi Kure, Shuji Moriguchi, Seiki Kawagoe, So Kazama, Kenjiro Terada

Engineering Geology　308　106808-106808　2022/10
Publisher: Elsevier BV
DOI： 10.1016/j.enggeo.2022.106808 　

ISSN： 0013-7952
Optimal probabilistic placement of facilities using a surrogate model for 3D tsunami simulations

Kenta Tozato, Shuji Moriguchi, Shinsuke Takase, Yu Otake, Michael R. Motley, Anawat Suppasri, Kenjiro Terada

2022/08/01
Publisher: Copernicus GmbH
DOI： 10.5194/nhess-2022-208 　

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Abstract. Tsunamis are associated with numerous uncertainties. Therefore, there has been an emphasis on setting the placement of infrastructure facilities based on probabilistic approaches. However, advanced numerical simulations have been often insufficiently utilized due to high computational costs. Therefore, in this study, we developed a framework that could efficiently utilize the information obtained from advanced numerical simulations for probabilistic assessment and investigation of the optimal placement of facilities based on calculated probability. Proper orthogonal decomposition (POD) techniques were employed for utilizing the data from the numerical simulations for probabilistic risk evaluation. We constructed a surrogate model in which POD was efficiently used to extract the spatial modes. The results of the numerical simulation were expressed as a linear combination of the modes, and the POD coefficients were expressed as a function of the uncertainty parameters to represent a result of an arbitrary scenario at a low computational cost. We conducted numerical simulations of the 2011 tsunami off the Pacific Coast caused by Tohoku Earthquake as an example of the method proposed in this study. The tsunami reached the target area, and the fault parameters of “slip” and “rake” were selected as the target uncertainties. We then created several scenarios in which these parameters were changed and conducted further numerical simulations using POD to construct a surrogate model. We selected the maximum inundation depth in the target area and the maximum impact force that acts on the buildings as the target risk indices, and we constructed a surrogate model of the spatial distributions of each indicator. Furthermore, we conducted Monte Carlo simulations using the constructed surrogate model and the information on fluctuations in uncertainties to calculate the spatial distribution of the failure criterion exceedance probabilities. We then used the Monte Carlo simulation results and a genetic algorithm to identify the optimal placement of facilities based on probability. We also discuss how the optimal placement changes according to differences in risk indices and the differences between parallel and series systems. The failure scenarios for each system are also discussed based on the failure probability. We show that the proposed method of efficiently utilizing advanced numerical simulation information was useful for conducting probabilistic hazard assessments and investigating the optimal placement of facilities based on probability theory.
Influence of strength and notch shape on crack initiation and propagation behavior of advanced high strength steel sheets

Masaki Omiya, Seiya Arakawa, Zhenduo Yao, Mayu Muramatsu, Shinnosuke Nishi, Kenji Takada, Masanobu Murata, Kazuaki Okato, Kensuke Ogawa, Kai Oide, Takaya Kobayashi, Jike Han, Kenjiro Terada

Engineering Fracture Mechanics　271　108573-108573　2022/08
Publisher: Elsevier BV
DOI： 10.1016/j.engfracmech.2022.108573 　

ISSN： 0013-7944
Two-scale topology optimization for transient heat analysis in porous material considering the size effect of microstructure

Naruethep Sukulthanasorn, Hiroya Hoshiba, Koji Nishiguchi, Mao Kurumatani, Robert Fleischhauer, Kuniharu Ushijima, Michael Kaliske, Kenjiro Terada, Junji Kato

Structural and Multidisciplinary Optimization　65　(7)　2022/07

DOI： 10.1007/s00158-022-03257-2 　

ISSN： 1615-147X

eISSN： 1615-1488
Generalized coordinate smoothed particle hydrodynamics with an overset method in total Lagrangian formulation

Huachao Deng, Yoshiaki Kawagoe, Yoshiaki Abe, Kenjiro Terada, Tomonaga Okabe

International Journal for Numerical Methods in Engineering　2022/06/03
Publisher: Wiley
DOI： 10.1002/nme.7043 　

ISSN： 0029-5981

eISSN： 1097-0207
Three-dimensional limit equilibrium slope stability analysis on real slope failures caused by heavy rain and earthquake

Saneiki FUJITA, Nilo Lemuel DOLOJAN, Shuji MORIGUCHI, Kenjiro TERADA, Takashi KYOYA

Japanese Geotechnical Journal　17　(2)　159-169　2022/06/01
Publisher: The Japanese Geotechnical Society
DOI： 10.3208/jgs.17.159 　

eISSN： 1880-6341
A CDM-like constitutive law for predicting degradation of strength and ductility of steel subjected to cyclic loading

Yuichi Shintaku, Seiichiro Tsutsumi, Kenjiro Terada

International Journal of Plasticity　153　2022/06

DOI： 10.1016/j.ijplas.2022.103237 　

ISSN： 0749-6419
Real-time tsunami risk evaluation method by synthetic dynamics and Bayesian update

NOMURA Reika, FUJITA Saneiki, OTAKE Yu, MORIGUCHI Shuji, KOSHIMURA Shunichi, TERADA Kenjiro, HASHIZUME Masahiro

Transactions of the Japan Society for Computational Engineering and Science　2022　20220003-20220003　2022/05/19
Publisher: JAPAN SOCIETY FOR COMPUTATIONAL ENGINEERING AND SCIENCE
DOI： 10.11421/jsces.2022.20220003 　

eISSN： 1347-8826

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This study presents a method of real-time tsunami risk evaluation by combined use of proper orthogonal decomposition (POD) and Bayesian update. The validity of the proposed method is demonstrated through the numerical example targeting plausible tsunamis induced by Nankai-Trough events. First, tsunami simulations are carried out for plausible tsunami scenarios determined by various patterns of fault rupture, and the time histories of wave heights are stored at selected synthetic gauge points. Then, POD is applied to the resulting data matrix of the synthetic dynamics (SD) composed of dynamics modes and coefficients, the latter of which represent scenario-specific information. In the real-time risk evaluation phase, the wave sequences of an actual tsunami event are sequentially measured at the synthetic gauge points and used to estimate the corresponding dynamics coefficients of the constructed SD. At the same time, by the application of Bayesian update, the likelihood of each of the dynamics coefficients pre-calculated for the selected tsunami scenarios is evaluated at each time and sequentially updated to detect the most probable scenario. Finally, the pre-calculated tsunami arrival time and inundation depth distribution corresponding to the detected scenario are determined as risk assessment indices seven minutes after the tsunami generation.
Rapid tsunami force prediction by mode-decomposition-based surrogate modeling

Kenta Tozato, Shinsuke Takase, Shuji Moriguchi, Kenjiro Terada, Yu Otake, Yo Fukutani, Kazuya Nojima, Masaaki Sakuraba, Hiromu Yokosu

NATURAL HAZARDS AND EARTH SYSTEM SCIENCES　22　(4)　1267-1285　2022/04

DOI： 10.5194/nhess-22-1267-2022 　

ISSN： 1561-8633

eISSN： 1684-9981
Submarine landslide source modeling using the 3D slope stability analysis method for the 2018 Palu, Sulawesi, tsunami

Chatuphorn Somphong, Anawat Suppasri, Kwanchai Pakoksung, Tsuyoshi Nagasawa, Yuya Narita, Ryunosuke Tawatari, Shohei Iwai, Yukio Mabuchi, Saneiki Fujita, Shuji Moriguchi, Kenjiro Terada, Cipta Athanasius, Fumihiko Imamura

Natural Hazards and Earth System Sciences　22　(3)　891-907　2022/03/17

DOI： 10.5194/nhess-22-891-2022 　

ISSN： 1561-8633

eISSN： 1684-9981
An implicit solution for an elastic-plastic model with hardening rule depending on plastic strain range using a primal-dual interior point method Peer-reviewed

SHINTAKU Yuichi, NAKAMURA Fumitoshi, TSUTSUMI Seiichiro, TERADA Kenjiro

Transactions of the Japan Society for Computational Engineering and Science　2022　20220001-20220001　2022/01/27
Publisher: JAPAN SOCIETY FOR COMPUTATIONAL ENGINEERING AND SCIENCE
DOI： 10.11421/jsces.2022.20220001 　

eISSN： 1347-8826

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The objective of this study is to improve numerical stability of an elastic-plastic model with memory surface that realizes various hardening behaviors under different ranges of cyclic loading by combination between a primal-dual interior point method and a return mapping algorithm. The primal-dual interior point method allows us to smoothly optimize a minimization problem with inequality constraints such as a yield function and memory surface. More specifically, the inequality condition is replaced with the equal condition by introducing the slack variable and the duality gap is gradually reduced by employing the path-following method. On the other hand, the primal-dual interior method could require bigger computational cost than the conventional return mapping method because of the increase of the unknown variable and the path-following method. Thus, an implicit solution for an elastic-plastic model with the memory surface is proposed by combining with the primal-dual interior point method and the return-mapping algorithm. In addition to the numerical cost, the numerical accuracy of the primal-dual interior point method is evaluated by the comparison with the conventional return mapping algorithm by an iso-error map that has been often applied for the conventional elastic-plastic models. After then, the capability of the proposed implicit method for an elastic-plastic model with the memory surface is demonstrated throughout the simple numerical examples.
QUANTIFICATION OF THE EFFECT OF ROCK SHAPE PROPARTIES ON THE DISTRIBUTION CHARACTERISTICS OF ROCKFALL RUN-OUT

Taiki YOSHIDA, Daiki WATANABE, Hasuka KANNO, Shuji MORIGUCHI, Kenjiro TERADA

Journal of Japan Society of Civil Engineers, Ser. C (Geosphere Engineering)　78　(3)　210-224　2022
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejge.78.3_210 　

eISSN： 2185-6516
Rapid prediction for rainfall-induced landslides in wide area using surrogate model of slope stability analysis

Tozato Kenta, Moriguchi Shuji, Terada Kenjiro

NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan　66　83　2022
Publisher: National Committee for IUTAM
DOI： 10.11345/japannctam.66.0_83 　

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This study presents a framework for rapid landslide prediction over a wide area using pre-computed results of infiltration analysis, surface flow analysis, and three-dimensional limit equilibrium-based slope stability analysis. After a series of numerical simulation are performed for different rainfall scenarios, a surrogate model is constructed with the help of the proper orthogonal decomposition and the Kriging method. The proposed framework is applied to a landslide risk analysis in consideration of actual terrain data. Obtained results show that the proposed framework has a high potential for rapid landslide risk analysis over a wide area.
Transient thermal porous structure designed by two-scale concurrent topology optimization

Naruethep Sukulthanasorn, Mao Kurumatani, Koji Nishiguchi, Junji Kato, Kenjiro Terada

Transactions of the Japan Society for Computational Engineering and Science　2022　2022

DOI： 10.11421/jsces.2022.20220004 　

eISSN： 1347-8826
Numerical simulation for deformation of laminates combining the novel shell element with the decoupled two-scale viscoelastic analysis of FRP

Takeki Yamamoto, Tomonaga Okabe, Kenjiro Terada

International Journal of Solids and Structures　234-235　111236-111236　2022/01
Publisher: Elsevier BV
DOI： 10.1016/j.ijsolstr.2021.111236 　

ISSN： 0020-7683
Substitution approach for decoupled two-scale analysis of materially nonlinear composite plates

Masami Sato, Mayu Muramatsu, Shinnosuke Nishi, Tatsuya Kawada, Kenjiro Terada

Computers and Structures　255　2021/10/15
Publisher: Elsevier Ltd
DOI： 10.1016/j.compstruc.2021.106623 　

ISSN： 0045-7949
Multiscale evaluation method of the drag effect on shallow water flow through coastal forests based on 3D numerical simulations

Reika Nomura, Shinsuke Takase, Shuji Moriguchi, Kenjiro Terada, Randall J. LeVeque

International Journal for Numerical Methods in Fluids　94　(1)　32-58　2021/10/11
Publisher: Wiley
DOI： 10.1002/fld.5046 　

ISSN： 0271-2091

eISSN： 1097-0363
Crack phase-field model equipped with plastic driving force and degrading fracture toughness for ductile fracture simulation

Jike Han, Seishiro Matsubara, Shuji Moriguchi, Michael Kaliske, Kenjiro Terada

Computational Mechanics　69　(1)　151-175　2021/09/23
Publisher: Springer Science and Business Media LLC
DOI： 10.1007/s00466-021-02087-1 　

ISSN： 0178-7675

eISSN： 1432-0924
Time‐Dependent Probabilistic Tsunami Inundation Assessment Using Mode Decomposition to Assess Uncertainty for an Earthquake Scenario

Yo Fukutani, Shuji Moriguchi, Kenjiro Terada, Yu Otake

Journal of Geophysical Research: Oceans　126　(7)　2021/07
Publisher: American Geophysical Union (AGU)
DOI： 10.1029/2021jc017250 　

ISSN： 2169-9275

eISSN： 2169-9291
Real-time Tsunami Force Prediction by Mode Decomposition-Based Surrogate Modeling

Kenta Tozato, Shinsuke Takase, Shuji Moriguchi, Kenjiro Terada, Yu Otake, Yo Fukutani, Kazuya Nojima, Masaaki Sakuraba, Hiromu Yokosu

2021/05/07
Publisher: Copernicus GmbH
DOI： 10.5194/nhess-2021-77 　

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Abstract. This study presents a framework for real-time tsunami force predictions by the application of mode decomposition based surrogate modelling with 2D-3D coupled numerical simulations. A limited number of large-scale numerical analyses are performed for a selection scenarios with variations in fault parameters to capture the distribution tendencies of the target risk indicators. Then, the proper orthogonal decomposition (POD) is applied to the analysis results to extract the principal modes that represent the temporal and spatial characteristics of tsunami forces. A surrogate model is then constructed by a linear combination of these modes, whose coefficients are defined as functions of the selected input parameters. A numerical example is presented to demonstrate the applicability of the proposed framework to one of the tsunami-affected areas during the Great East Japan Earthquake of 2011. Combining 2D and 3D versions of the stabilized finite element method, we carry out a series of high precision numerical analyses with different input parameters to obtain a set of time history data of the tsunami forces acting on buildings and the inundation depths. POD is applied to the data set to construct the surrogate model that is capable of providing the predictions equivalent to the simulation results almost instantaneously. Based on the acceptable accuracy of the obtained results, it was confirmed that the proposed framework is a useful tool for evaluating time series data of hydrodynamic force acting on buildings.
Thermo-mechanical coupled incremental variational formulation for thermosetting resins subjected to curing process

Yosuke Yamanaka, Seishiro Matsubara, Risa Saito, Shuji Moriguchi, Kenjiro Terada

International Journal of Solids and Structures　216　30-42　2021/05/01

DOI： 10.1016/j.ijsolstr.2021.01.014 　

ISSN： 0020-7683
Chemomechanical Simulation of LiF-Rich Solid–Electrolyte Interphase Formed from Fluoroethylene Carbonate on a Silicon Anode

Yuki Kamikawa, Koji Amezawa, Kenjiro Terada

ACS Applied Energy Materials　4　(4)　3231-3239　2021/04/26
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acsaem.0c03014 　

ISSN： 2574-0962

eISSN： 2574-0962
A computational design optimization method for rockfall protection embankments

Hasuka Kanno, Shuji Moriguchi, Shunsuke Hayashi, Kenjiro Terada

Engineering Geology　284　2021/04

DOI： 10.1016/j.enggeo.2020.105920 　

ISSN： 0013-7952
Extended B-spline-based implicit material point method

Yuya Yamaguchi, Shuji Moriguchi, Kenjiro Terada

International Journal for Numerical Methods in Engineering　122　(7)　1746-1769　2021/04

DOI： 10.1002/nme.6598 　

ISSN： 0029-5981

eISSN： 1097-0207
A variationally consistent formulation of the thermo-mechanically coupled problem with non-associative viscoplasticity for glassy amorphous polymers

Seishiro Matsubara, Kenjiro Terada

International Journal of Solids and Structures　212　152-168　2021/03/01

DOI： 10.1016/j.ijsolstr.2020.12.004 　

ISSN： 0020-7683
Energy-Loss Near-Edge Structures and Low-Loss Structures of Polymers in a Solid Electrolyte Interface Formed from Fluoroethylene Carbonate on a Si Anode Clarified by DFT Calculations

Yuki Kamikawa, Koji Amezawa, Kenjiro Terada

The Journal of Physical Chemistry C　125　(7)　3890-3900　2021/02/25
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.jpcc.0c10204 　

ISSN： 1932-7447

eISSN： 1932-7455
A decoupling scheme for two-scale finite thermoviscoelasticity with thermal and cure-induced deformations

Risa Saito, Yosuke Yamanaka, Seishiro Matsubara, Tomonaga Okabe, Shuji Moriguchi, Kenjiro Terada

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING　122　(4)　1133-1166　2021/02

DOI： 10.1002/nme.6575 　

ISSN： 0029-5981

eISSN： 1097-0207
A Gurson model improved by cohesive traction-separation law to realize transition from ductile to brittle fracture

Takuya Kagimura, Yuichi Shintaku, Seiichiro Tsutsumi, Kenjiro Terada

Yosetsu Gakkai Ronbunshu/Quarterly Journal of the Japan Welding Society　38　(2)　126S-130S　2021

DOI： 10.2207/QJJWS.38.126S 　

ISSN： 0288-4771
EFFECT OF PARTICLE SIZE DISTRIBUTIONS ON GRANULAR FLOW SIMULATIONS USING DISCRETE ELEMENT METHOD

Daiki WATANABE, Shuji MORIGUCHI, Kenjiro TERADA

Journal of Japan Society of Civil Engineers, Ser. C (Geosphere Engineering)　77　(4)　392-402　2021
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejge.77.4_392 　

eISSN： 2185-6516
Ductile fracture crack phase-field model equipped with a novel degrading fracture toughness

HAN Jike, MURATA Masanobu, MORIGUCHI Shuji, TERADA Kenjiro, MATSUBARA Seishiro, NISHI Shinnosuke, TAKADA Kenji, MURAMATSU Mayu, OMIYA Masaki, OGAWA Kensuke, OIDE Kai, KOBAYASHI Takaya

Transactions of the Japan Society for Computational Engineering and Science　2021　20210014-20210014　2021
Publisher: JAPAN SOCIETY FOR COMPUTATIONAL ENGINEERING AND SCIENCE
DOI： 10.11421/jsces.2021.20210014 　

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This study aims to enhance the crack phase-field model for ductile fracture by introducing a novel degrading fracture toughness to reflect damage evolution based on the phenomenological justification for the failure mechanism in elastoplastic materials. The free energy consists of elastic, pseudo-plastic and crack components. The governing equations are derived as stationary conditions for the corresponding local and global optimization problems within the continuum thermodynamics framework. Then, we introduce a degrading fracture toughness to reflect the evolution of micro-defects and their coalescences that are caused by both plastic deformation and negative hydrostatic pressure. Equipped with this implement, the proposed crack phase-field model realizes the reduction of both stiffness and fracture toughness to simulate the failure phenomena of elastoplastic materials. Two numerical examples are presented to demonstrate the capability of the proposed model in reproducing typical ductile fracture behaviors.
MPM–FEM hybrid method for granular mass–water interaction problems

Shaoyuan Pan, Yuya Yamaguchi, Anawat Suppasri, Shuji Moriguchi, Kenjiro Terada

Computational Mechanics　2021

DOI： 10.1007/s00466-021-02024-2 　

ISSN： 0178-7675

eISSN： 1432-0924
Correction to: Mapping method of rainfall-induced landslide hazards by infiltration and slope stability analysis: A case study in Marumori, Miyagi, Japan, during the October 2019 Typhoon Hagibis (Landslides, (2021), 10.1007/s10346-020-01617-x)

Nilo Lemuel J. Dolojan, Shuji Moriguchi, Masakazu Hashimoto, Kenjiro Terada

Landslides　2021

DOI： 10.1007/s10346-021-01642-4 　

ISSN： 1612-510X

eISSN： 1612-5118
FE ^r method with surrogate localization model for hyperelastic composite materials

Ryo Hatano, Seishiro Matsubara, Shuji Moriguchi, Kenjiro Terada, Julien Yvonnet

Advanced Modeling and Simulation in Engineering Sciences　7　(1)　2020/12/01

DOI： 10.1186/s40323-020-00175-0 　

eISSN： 2213-7467
Advances of International Collaboration on M9 Disaster Science: Scientific Session Report

Elizabeth Maly, Kenjiro Terada, Randall J. LeVeque, Naoko Kuriyama, Daniel B. Abramson, Lan T. Nguyen, Ann Bostrom, Jorge León, Michael Motley, Patricio A. Catalan, Shunichi Koshimura, Shuji Moriguchi, Yuya Yamaguchi, Carrie Garrison-Laney, Anawat Suppasri, Erick Mas

Journal of Disaster Research　15　(7)　890-899　2020/12/01
Publisher: Fuji Technology Press Ltd.
DOI： 10.20965/jdr.2020.p0890 　

ISSN： 1881-2473

eISSN： 1883-8030

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The goal of the Scientific Session: “Advances of International Collaboration on M9 Disaster Science” at the 2nd World Bosai Forum (WBF) in Sendai in November 2019 was to share progress on research projects and findings related to an M9 mega-disaster event, building on outcomes from a March 2019 collaborative workshop on M9 disaster science between research partners from the International Research Institute of Disaster Science (IRIDeS)/Tohoku University, University of Washington-Seattle (UW), and the Research Center for Integrated Disaster Risk Management (CIGIDEN). This paper reports on the presentations during the WBF Scientific Session, which shared updates and outputs of research collaborations from different disciplines, following the themes of risk-based planning, structural engineering, tsunami observation and early warning, and tsunami simulation and probabilistic tsunami risk assessment. This international and cross-disciplinary collaboration has led to the advancement of a number of specific research projects in different fields, as well as a robust network of researchers in the three countries. Based in coastal regions facing similar risks of massive earthquakes and tsunami in Japan, the United States, and Chile, it is hoped that ongoing and future collaboration within this network will continue to advance knowledge of disaster science and international disaster risk reduction.
Elastic–Plastic Deformation of a Solid Electrolyte Interface Formed by Reduction of Fluoroethylene Carbonate: A Nanoindentation and Finite Element Analysis Study

Yuki Kamikawa, Koji Amezawa, Kenjiro Terada

The Journal of Physical Chemistry C　124　(41)　22488-22495　2020/10/15
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.jpcc.0c06420 　

ISSN： 1932-7447

eISSN： 1932-7455
First-Principles Study on the Mechanical Properties of Polymers Formed by the Electrochemical Reduction of Fluoroethylene Carbonate and Vinylene Carbonate Peer-reviewed

Yuki Kamikawa, Koji Amezawa, Kenjiro Terada

The Journal of Physical Chemistry C　124　(37)　19937-19944　2020/09/17
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.jpcc.0c04878 　

ISSN： 1932-7447

eISSN： 1932-7455
An Elastic-plastic Constitutive Law Embedding Cohesive Cracks with Plasticity-induced Damage to Realize Degradation of Strength and Toughness under Cyclic Loading Peer-reviewed

Yuichi Shintaku, Katsuya Soejima, Seiichiro Tsutsumi, Kenjiro Terada

Tetsu-to-Hagane　106　(9)　662-671　2020/09

DOI： 10.2355/tetsutohagane.TETSU-2019-121 　

ISSN： 0021-1575
Probabilistic tsunami hazard assessment with simulation-based response surfaces

T. Kotani, K. Tozato, S. Takase, S. Moriguchi, K. Terada, Y. Fukutani, Y. Otake, K. Nojima, M. Sakuraba, Y. Choe

Coastal Engineering　160　103719-103719　2020/09
Publisher: Elsevier BV
DOI： 10.1016/j.coastaleng.2020.103719 　

ISSN： 0378-3839
Decoupled two-scale viscoelastic analysis of FRP in consideration of dependence of resin properties on degree of cure Peer-reviewed

Risa Saito, Yuya Yamaguchi, Seishiro Matsubara, Shuji Moriguchi, Yasuko Mihara, Takaya Kobayashi, Kenjiro Terada

International Journal of Solids and Structures　190　199-215　2020/05/01

DOI： 10.1016/j.ijsolstr.2019.11.010 　

ISSN： 0020-7683
Isogeometric topology optimization of anisotropic metamaterials for controlling high‐frequency electromagnetic wave Peer-reviewed

Shinnosuke Nishi, Takayuki Yamada, Kazuhiro Izui, Shinji Nishiwaki, Kenjiro Terada

International Journal for Numerical Methods in Engineering　121　(6)　1218-1247　2020/03/30
Publisher: Wiley
DOI： 10.1002/nme.6263 　

ISSN： 0029-5981

eISSN： 1097-0207
3D crystal plasticity analyses on the role of hard/soft inclusions in the local slip formation International-coauthorship Peer-reviewed

Riccardo Fincato, Seiichiro Tsutsumi, Tatsuo Sakai, Kenjiro Terada

International Journal of Fatigue　134　105518　2020/02

DOI： 10.1016/j.ijfatigue.2020.105518 　

ISSN： 0142-1123
数値解析結果の空間モード分解による津波のリスク評価 Peer-reviewed

外里健太, 小谷拓磨, 波多野僚, 高瀬慎介, 森口周二, 寺田賢二郎, 大竹雄

計算工学会論文集　p.20200003　2020/02
A phase-field ductile fracture model with a variable regularization length parameter

Jike Han, Shinnosuke Nishi, Kenji Takada, Mayu Muramatsu, Masaki Omiya, Kensuke Ogawa, Kai Oide, Takuya Kobayashi, Masanobu Murata, Shuji Moriguchi, Kenjiro Terada

Transactions of the Japan Society for Computational Engineering and Science　2020　1-15　2020

DOI： 10.11421/jsces.2020.20200005 　

eISSN： 1347-8826
Tsunami risk assessment using spatial modes extracted from results of numerical analysis

Kenta Tozato, Takuma Kotani, Ryo Hatano, Shinsuke Takase, Shuji Moriguchi, Kenjiro Terada, Yu Otake

Transactions of the Japan Society for Computational Engineering and Science　2020　2020

DOI： 10.11421/jsces.2020.20200003 　

eISSN： 1347-8826
Incremental variational formulation of time evolution of cure-degree along with viscoelasticity for thermosetting resins

Yosuke Yamanaka, Seishiro Matsubara, Risa Saito, Shuji Moriguchi, Kenjiro Terada

Transactions of the Japan Society for Computational Engineering and Science　2020　1　2020

DOI： 10.11421/jsces.2020.20200011 　

eISSN： 1347-8826
QUANTIFICATION OF PARAMETER CONTRUBUTION IN GRANULAR FLOW SIMULATIONS USING THE DISCRETE ELEMENT METHOD

Shuji MORIGUCHI, Hiroki OKUYAMA, Kenjiro TERADA, Yu OTAKE, Takayuki AOKI

Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM))　76　(2)　I_369-I_377　2020
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.76.2_i_369 　

eISSN： 2185-4661
SPATIAL UNCERTAINTY EVALUATION BY MODE DECOMPOSITION OF WATER DEPTH COEFFICIENTS USED FOR TSUNAMI LOADS DESSIGN

Yo FUKUTANI, Shuji MORIGUCHI, Kenjiro TERADA, Yoshinori SHIGIHARA

Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering)　76　(2)　I_295-I_300　2020
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/kaigan.76.2_i_295 　

ISSN： 1884-2399

eISSN： 1883-8944
Viscoelastic-viscoplastic combined constitutive model for glassy amorphous polymers under loading/unloading/no-load states Peer-reviewed

Seishiro Matsubara, Kenjiro Terada, Ryusei Maeda, Takaya Kobayashi, Masanobu Murata, Takuya Sumiyama, Kenji Furuichi, Chisato Nonomura

Engineering Computations (Swansea, Wales)　2020

DOI： 10.1108/EC-05-2019-0197 　

ISSN： 0264-4401
Numerical analysis of crack propagation with cleavage fracture and depdendence of toughness on hydrogen concentration

So ISHIBASHI, Yuichi SHINTAKU, Kenjiro TERADA, Seiichiro TSUTSUMI

Proceedings of National Symposium on Welding Mechanics and Design 2019　98-101　2019/12
Finite thermo-elastic decoupled two-scale analysis Peer-reviewed

Robert Fleischhauer,Tom Thomas, Junji Kato, Kenjiro Terada, Michael Kaliske

International Journal for Numerical Methods in Engineering　2019/08/28

DOI： 10.1002/nme.6212 　
Influence of hard and soft inclusions inside a ferritic matrix

Riccardo FINCATO, Seiichiro TSUTSUMI, Tatsuo SAKAI, Kenjiro TERADA

Proc. 12th international conference on multiaxial fatigue and fracture　1-10　2019/06
Microscopic design and optimization of hydrodynamically lubricated dissipative interfaces Peer-reviewed

B.A. Cakal, İ. Temizer, J. Kato, K. Terada

International Journal of Numerical Methods for Engineering　2019/05/26

DOI： 10.1002/nme.6129 　
Numerical Analysis of Crack Propagation due to Hydrogen Embrittlement with Anisotropic Behavior of Cleavage Fracture

So Ishibashi, Yuuishi Shintaku, Seiichiro Tsutsumi, Kenjiro Terada

Proceedings of the conference on computational engineering and science　24　1-4　2019/05
Cohesive-traction Embedded Elasto-plastic Model with Combined Isotropic-kinematic Hardening for Fatigue Lifetime Prediction

Katsuya Soejima, Yuuishi Shintaku, Seiichiro Tsutsumi, Kenjiro Terada

Proceedings of the conference on computational engineering and science　24　1-4　2019/05
Simulations of cohesive fracture behavior of reinforced concrete by a fracture-mechanics-based damage model

Mao Kurumatani, Yuto Soma, Kenjiro Terada

Engineering Fracture Mechanics　206　392-407　2019/02/01
Publisher: Elsevier Ltd
DOI： 10.1016/j.engfracmech.2018.12.006 　

ISSN： 0013-7944
Numerical simulation of rock slope failure with dynamic frictional contact based on co-rotational technique

S. Suzuki, K. Takashi, K. Terada, S. Moriguchi, N. Takeuchi

Rock Dynamics Summit - Proceedings of the 2019 Rock Dynamics Summit, RDS 2019　446-450　2019

DOI： 10.1201/9780429327933-72 　
Simulation-based optimal design approach for rockfall protection walls

S. Moriguchi, H. Kanno, K. Terada, T. Kyoya

Rock Dynamics Summit - Proceedings of the 2019 Rock Dynamics Summit, RDS 2019　481-485　2019

DOI： 10.1201/9780429327933-78 　
A data-driven micro-macro coupled multiscale analysis for hyperelastic composite materials Peer-reviewed

HATANO Ryo, MATSUBARA Seishiro, MORIGUCHI Shuji, TERADA Kenjiro

Transactions of the Japan Society for Computational Engineering and Science　2019　(0)　20190015-20190015　2019
Publisher: 一般社団法人日本計算工学会
DOI： 10.11421/jsces.2019.20190015 　

eISSN： 1347-8826
Achievements of NEDO Durability Projects on SOFC Stacks in the Light of Physicochemical Mechanisms Peer-reviewed

H. Yokokawa, M. Suzuki, M. Yoda, T. Suto, K. Tomida, K. Hiwatashi, M. Shimazu, A. Kawakami, H. Sumi, M. Ohmori, T. Ryu, N. Mori, M. Iha, S. Yatsuzuka, K. Yamaji, H. Kishimoto, K. Develos-Bagarinao, T. Shimonosono, K. Sasaki, S. Taniguchi, T. Kawada, M. Muramatsu, K. Terada, K. Eguchi, T. Matsui, H. Iwai, M. Kishimoto, N. Shikazono, Y. Mugikura, T. Yamamoto, M. Yoshikawa, K. Yasumoto, K. Asano, Y. Matsuzaki, K. Sato, T. Somekawa

Fuel Cells　19　(4)　311-339　2019

DOI： 10.1002/fuce.201800187 　

ISSN： 1615-6846

eISSN： 1615-6854
Tsunami hazard and risk assessment for multiple buildings by considering the spatial correlation of wave height using copulas Peer-reviewed

Yo Fukutani, Shuji Moriguchi, Kenjiro Terada, Takuma Kotani, Yu Otake, Toshikazu Kitano

Nat. Hazards Earth Syst. Sci.　19　(11)　2619-2634　2019
Publisher: Copernicus GmbH
DOI： 10.5194/nhess-19-2619-2019 　

eISSN： 1684-9981

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Abstract. It is necessary to evaluate aggregate damage probability to multiple buildings when performing probabilistic risk assessment for the buildings. The purpose of this study is to demonstrate a method of tsunami hazard and risk assessment for two buildings far away from each other, using copulas of tsunami hazards that consider the nonlinear spatial correlation of tsunami wave heights. First, we simulated the wave heights considering uncertainty by varying the slip amount and fault depths. The frequency distributions of the wave heights were evaluated via the response surface method. Based on the distributions and numerically simulated wave heights, we estimated the optimal copula via maximum likelihood estimation. Subsequently, we evaluated the joint distributions of the wave heights and the aggregate damage probabilities via the marginal distributions and the estimated copulas. As a result, the aggregate damage probability of the 99th percentile value was approximately 1.0 % higher and the maximum value was approximately 3.0 % higher while considering the wave height correlation. We clearly showed the usefulness of copula modeling considering the wave height correlation in evaluating the probabilistic risk of multiple buildings. We only demonstrated the risk evaluation method for two buildings, but the effect of the wave height correlation on the results is expected to increase if more points are targeted.
A Prototype Seismic Loss Assessment Tool Using Integrated Earthquake Simulation

Panon Latcharote, Kenjiro Terada, Muneo Hori, Fumihiko Imamura

International Journal of Disaster Risk Reduction　31　1354-1365　2018/10

DOI： 10.1016/j.ijdrr.2018.03.026 　

ISSN： 2212-4209
Solid-liquid coupled material point method for simulation of ground collapse with fluidization Peer-reviewed

Y. Yamaguchi, S. Takase, S. Moriguchi, K. Terada

Computational Particle Mechanics　2018/06
Shape deformation analysis of anode-supported solid oxide fuel cell by electro-chemo-mechanical simulation

Mayu Muramatsu, Masami Sato, Kenjiro Terada, Satoshi Watanabe, Keiji Yashiro, Tatsuya Kawada, Fumitada Iguchi, Harumi Yokokawa

Solid State Ionics　319　194-202　2018/06/01
Publisher: Elsevier B.V.
DOI： 10.1016/j.ssi.2018.01.027 　

ISSN： 0167-2738
Advanced topology optimization Peer-reviewed

Shinji Nishiwaki, Kenjiro Terada

International Journal for Numerical Methods in Engineering　113　(8)　1145-1147　2018/02/24
Publisher: John Wiley and Sons Ltd
DOI： 10.1002/nme.5703 　

ISSN： 1097-0207 0029-5981
Micro-macro concurrent topology optimization for nonlinear solids with a decoupling multiscale analysis Peer-reviewed

Junji Kato, Daishun Yachi, Takashi Kyoya, Kenjiro Terada

International Journal for Numerical Methods in Engineering　113　(8)　1189-1213　2018/02/24
Publisher: John Wiley and Sons Ltd
DOI： 10.1002/nme.5571 　

ISSN： 1097-0207 0029-5981
Two-scale topology optimization for composite plates with in-plane periodicity Peer-reviewed

Shinnosuke Nishi, Kenjiro Terada, Junji Kato, Shinji Nishiwaki, Kazuhiro Izui

International Journal for Numerical Methods in Engineering　113　(8)　1164-1188　2018/02/24
Publisher: John Wiley and Sons Ltd
DOI： 10.1002/nme.5545 　

ISSN： 1097-0207 0029-5981
３次元解析に基づく雪崩の危険度マップ Peer-reviewed

鬼頭昂平, 小谷拓磨, 山口裕矢, 高瀬慎介, 森口周二, 寺田賢二郎

土木学会論文集A2（応用力学）　84　(2)　I_203-I_211　2018/02
固液混合流体の直接数値シミュレーションによる巨視的粘性評価 Peer-reviewed

野村怜佳, 高瀬慎介, 森口周二, 寺田賢二郎

計算工学会論文集　p.20182007　2018/02
路線における落石対策工の最適配置評価のための統計モデリング Peer-reviewed

菅野蓮華, 森口周二, 寺田賢二郎, 林俊介, 磯部有作, 岩永昇二

応用力学論文集　74　(2)　I_13-I_21　2018/02
Viscosity evaluation of solid-liquid mixture based on direct numerical simulation

Reika Nomura, Shinsuke Takase, Shuji Moriguchi, Kenjiro Terada

Transactions of the Japan Society for Computational Engineering and Science　2018　(2)　2018/01/01

DOI： 10.11421/jsces.2018.20182007 　

eISSN： 1347-8826
A method of numerical viscosity measurement for solid-liquid mixture Peer-reviewed

Reika Nomura, Kenjiro Terada, Shinsuke Takase, Shuji Moriguchi

Lecture Notes in Applied and Computational Mechanics　86　347-363　2018
Publisher: Springer Verlag
DOI： 10.1007/978-3-319-65463-8_17 　

ISSN： 1613-7736
A viscoelastic-viscoplastic combined constitutive model for thermoplastic resins Peer-reviewed

Seishiro Matsubara, Kenjiro Terada

Computational Methods in Applied Sciences　46　243-264　2018
Publisher: Springer Netherland
DOI： 10.1007/978-3-319-60885-3_12 　

ISSN： 1871-3033
応答曲面法を用いた確率論的津波損害評価－相模トラフ地震への適用－ Peer-reviewed

福谷陽, 森口周二, 小谷拓磨, 寺田賢二郎

土木学会論文集B2（海岸工学）　74　(2)　I-463-I-468　2018
A Tsunami Risk Analysis Considering Correlations Among Coastal Cities Peer-reviewed

Takuma Kotani, Shuji Moriguchi, Kenjiro Terada, Shinsuke Takase, Yu Otake, Yo Fukutani, Masaaki Sakuraba

7th Asia Conference on Earthquake Engineering　2018
Simulation of ferroelastic phase formation using phase-field model

M. Muramatsu, K. Yashiro, T. Kawada, K. Terada

International Journal of Mechanical Sciences　146-147　462-474　2018
Publisher: Elsevier Ltd
DOI： 10.1016/j.ijmecsci.2017.12.027 　

ISSN： 0020-7403
Anisotropic Damage Constitutive Law for Cleavage Failure in Crystalline Grain by Cohesive Zone Model Peer-reviewed

Yuichi Shintaku, Kenjiro Terada, Seiichiro Tsutsumi

Quarterly Journal of the Japan Welding Society　35　(2)　165s-168s　2017/12

DOI： 10.2207/QJJWS.35.165S 　

ISSN： 0288-4771
Characterization of transition from Darcy to non-Darcy flow with 3D pore-level simulations Peer-reviewed

Ikkoh Tachibana, Shuji Moriguchi, Shinsuke Takase, Kenjiro Terada, Takayuki Aoki, Kohji Kamiya, Takeshi Kodaka

SOILS AND FOUNDATIONS　57　(5)　707-719　2017/10

DOI： 10.1016/j.sandf.2017.08.003 　

ISSN： 0038-0806
Three-dimensional nonstructural finite element analysis \\ of snow avalanche using non-Newtonian fluid model Peer-reviewed

Yuya YAMAGUCHI, Shinsuke TAKASE, Shuji MORIGUCHI, Kenjiro TERADA, Kennichi ODA, Isao KAMIISHI

Transactions of JSCES　p. 20170011　2017/08/29

DOI： 10.11421/jsces.2017.20170011 　

eISSN： 1347-8826
RESEARCH TRENDS OF COMPUTATIONAL SOLID MECHANICS AND THEIR PRACTICAL APPLICATIONS Peer-reviewed

Takuya KOBAYASHI, Kenjiro TERADA

社会技術研究論文集　14　167-177　2017/07
有限ひずみ損傷モデルを用いた断層の動きに伴う表層地盤変状解析 Peer-reviewed

大川真里菜, 鈴木峻, 高瀬慎介, 森口周二, 寺田賢二郎, 車谷麻緒

73　(2)　I_497-I_505　2017/06
個別要素法に音づく落石防護工の最適設計手法に関する基礎的研究 Peer-reviewed

菅野蓮華, 森口周二, 高瀬慎介, 寺田賢二郎

73　(2)　i_469-I_476　2017/06
浅水長波方程式を用いた有限被覆法に基づく構造流体連成解析 Peer-reviewed

高瀬慎介, 山口裕矢, 森口周二, 寺田賢二郎, 野島和也, 櫻庭雅明

73　(2)　I_305-I_312　2017/06
Materials properties for the simulation of electro-chemo-mechanical coupling behavior of SOFC Peer-reviewed

K. Yashiro, T. Kawada, S. Watanabe, M. Muramatsu, T. Sakamoto, S. I. Hashimoto, K. Terada, M. Sato, T. Hashida, K. Sato, F. Iguchi, H. Yugami, K. Amezawa, T. Nakamura, Y. Kimura, A. Unemoto

ECS Transactions　78　(1)　2309-2316　2017/05/30
Publisher: Electrochemical Society Inc.
DOI： 10.1149/07801.2309ecst 　

ISSN： 1938-6737 1938-5862

eISSN： 1938-6737
結合力埋込型損傷構成則の疲労問題への適用

新宅勇一, 堤成一郎, 寺田賢二郎

日本計算工学会計算工学講演会論文集　22　E07-4-1-E07-4-4　2017/05
Numerical and experimental study on a finite deformation model for elastic-plastic materials with two damage variables for residual strength assessment after cyclic loading

22　D01-3-1-D01-3-4　2017/05
Publisher:
On the treatments of heterogeneities and periodic boundary conditions for isogeometric homogenization analysis Peer-reviewed

Seishiro Matsubara, Shin-Nosuke Nishi, Kenjiro Terada

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING　109　(11)　1523-1548　2017/03

DOI： 10.1002/nme.5328 　

ISSN： 0029-5981

eISSN： 1097-0207
Simulation Technology on SOFC Durability With an Emphasis on Conductivity Degradation of ZrO2-Base Electrolyte Peer-reviewed

Harumi Yokokawa, Haruo Kishimoto, Taro Shimonosono, Katsuhiko Yamaji, Mayu Muramatsu, Kenjiro Terada, Keiji Yashiro, Tatsuya Kawada

JOURNAL OF ELECTROCHEMICAL ENERGY CONVERSION AND STORAGE　14　(1)　011004　2017/02

DOI： 10.1115/1.4036038 　

ISSN： 2381-6872

eISSN： 2381-6910
A simulation of large scale sediment flow experiment using DEM Peer-reviewed

Masai SATO, Mayu MURAMATSU, Kenjiro TERADA, Satoshi WATANABE, Keiji YASHIRO, Tatsuya KAWADA, Harumi YOKOKAWA

Transactions of JSCES　20170004　2017/01/29

DOI： 10.11421/jsces.2017.20170004 　
A simulation of large scale sediment flow experiment using DEM Peer-reviewed

Shoji MORIGUCHI, Yuma OHTA, Shinsuke TAKASE, Kenjiro TERADA, Keita ABSE, Takayuki AOKI

土木学会論文集A2（応用力学）　72　(2)　I_449-I_457　2017/01/29
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.72.I_449 　

eISSN： 2185-4661

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In order to study suitable calculation conditions for estimating impact force of sediment flow using DEM, a simulation of a large scale sediment flow experiment was performed. By changing element size and element shape, the effects of thease factors were investigated in the simulation. Based on the obtained results, importance of element size and flow chracteristics of the spherical ekement and non-sherical eklement are analyzed. In addition, a flow of the estimation process is proposed, and some points of attention are summarized from the view points of engineering.
コンクリートの破壊力学と修正von-Mises基準に基づく等方性の有限ひずみ損傷モデル Peer-reviewed

Mao KURUMATANI, Shunitsu ABE, Yuto SOMA, Kenjiro TERADA

A finite stain isotropic damage model for concrete based on fracture mechanics and modified von-Mises criterion　73　(1)　11-21　2017/01/20
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.73.11 　

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 This paper presents a finite strain isotropic damage model for finite deformation FE analyses of crack propagations in concrete and reinforced concrete. The modified von-Mises criterion is extended to finite deformation problem for evaluating damage. The evolution of the damage variables is defined as the traction — separation law which is based on fracture mechanics for concrete. We first show the formulation of the proposed finite strain damage model with the modified von-Mises criterion. Several numerical experiments are presented for verification and validation of the proposed model. The mesh sensitivity in crack propagation FE analyses is verified in 1-D and 3-D problems. The FE numerical results with the damage model are then compared with the own experimental test results of 4-point bend test of RC beam without shear reinforcements.
NUMERICAL PLATE TESTING FOR NON-LINEAR MULTI-SCALE ANALYSIS OF PLATE-SHAPED DEVICE Peer-reviewed

SATO Masami, MURAMATSU Mayu, MATSUBARA Seishiro, NISHI Shinnosuke, TERADA Kenjiro, YASHIRO Keiji, KAWADA Tatsuya

Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM))　73　(2)　I_283-I_294　2017
Publisher: 公益社団法人土木学会

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We propose a new method of multi-scale analysis for plate-like devices such as a flat plate cell of solid oxide fuel cell (SOFC), which is classified into a composite plate composed of in-plane periodic structures. To characterize the macroscopic nonlinear mechanical behavior of the in-plane periodic structure, the method of numerical plate testing is employed. Since the obtained relationships between macroscopic generalized strains and stress cannot be represented by an equivalent homogeneous plate with a single material, we introduce a surrogate model composed of homogeneous layers that is expected to exhibit the same macroscopic responses. After the material parameters of these layers are identified, the macroscopic analysis becomes possible by use of a laminated structure with continuum solid shell elements available in a general-purpose finite element program. Representative numerical examples are presented to demonstrate the capability of the proposed multi-scale analysis method.
An analysis of propagating discontinuity using finite cover method with cohesive-traction embedded damage-like constitutive law

SHINTAKU,Yuichi, TERADA,Kenjiro, TSUTSUMI,Seiichiro

The Proceedings of The Computational Mechanics Conference　2017　286　2017
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmecmd.2017.30.286 　

ISSN： 2424-2799
EFFECTS OF SPATIAL CHARACTERISTICS OF SLOPE PROPERTIES IN ROCKFALL SIMULATIONS USING DEM Peer-reviewed

UEHARA Naohide, TACHIBANA Ikkoh, KANNO Hasuka, MORIGUCHI Shuji, TERADA Kenjiro, TAKASE Shinsuke, OTAKE Yu

Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM))　73　(2)　I_507-I_516　2017
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.73.I_507 　

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This study presents a numerical study on effects of spatial characteristics of slopes in rockfall simulations using DEM. A series of DEM simulations of a model experiment were performed under the different calcu- lation conditions and different spatial characteristics of slope, and effects of these factors were quantified. Based on the obtained results, it was found the accuracy of the mean values of input parameters is much more important than considering the spatial characteristics. However the conclusion is limited to simulated results obtained in this study, hence more detailed verification is necessary.
Spatial and probabilistic risk evaluation of rockfalls using Gaussian mixture model Peer-reviewed

Hasuka KANNO, Shoji MORIGUCHI, Shinsuke TAKASE, Kenjiro TERADA, Kazuhide SAWADA, Masanori KONAMI

Japanese Geotechnical Journal　12　(2)　211-221　2017

DOI： 10.3208/jgs.12.211 　
Multiscale topology optimization for composite plates undergoing thermal displacement Peer-reviewed

Shinnosuke NISHI, Kenjiro TERADA, Junji KATO, Shinji NISHIWAKI, Kazuhiro IZUI

Transactions of JSCES　20160024　20160024-20160024　2016/11/15
Publisher: JAPAN SOCIETY FOR COMPUTATIONAL ENGINEERING AND SCIENCE
DOI： 10.11421/jsces.2016.20160024 　

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The present study proposes a multiscale topology optimization method of cross-section structures that control the macroscopic thermal deformations of a thick composite plates. The proposed optimization method is based on the two-scale composite plate model, in which thick plate theory is employed at macro-scale, while three-dimensional solids are assumed for in-plane periodic microstructures (unit cells) whose scale is comparable with the plate’s thickness. The process of the in-plane homogenization in a two-scale analysis corresponds to numerical plate testings (NPTs) to compute the macroscopic plate stiffness of the thick plate. In addition, the co-rotational formulation is employed to account for large displacement and rotation of the macroscopic plate structure, whereas material models used in in-plane unit cells, are assumed to be linearly elastic. The optimization problem that controls a nodal displacement of the macrostructure is selected as numerical examples, and their solutions are provided to demonstrate the capability of the proposed method.
Constitutive equations of earthenware material during firing processes and determination of their function forms Peer-reviewed

Seishiro MATSUBARA, Toshiyuki SAITOU, Kai OIDE, Hiroto SHIN, Manabu UMEDA, Yasuhiro KATSUDA, Yasuko MIHARA, Takaya KOBAYASHI, Kenjiro TERADA

Transactions of the JSME (in Japanese)　82　(840)　16-00171-00266-16-00266　2016/11/07
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/transjsme.16-00266 　

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We propose a set of constitutive equations of earthenware material subjected to the firing process and appropriate ways of determining their function forms and relevant material parameters from a series of respective experiments. The firing process under a specific heat curves is generally divided into three different phases; "thermal dilatation phase", "sintering phase" and "thermal contraction phase". These non-mechanical deformations are assumed not to be coincident, and the mechanical ones are assumed to be represented by viscoplastic constitutive model. Then, the key issue must be how to determine sintering strains by calibrating the employed function form of the densification rate with the data obtained from the stairway thermal cycle (STC) tests. Also, the presentations of the dependencies of the elastic and creep properties on both temperature and density are of particular importance to accurately predict the overall deformation of earthware. All the relevant material parameters as well as coefficients of thermal expansion and contraction are identified with the data obtained from respective mechanical experiments conducted in testing equipments for thermo-mechanical analysis (TMA) under several levels of termperature. The method of differential evolution, which is one of the metaheuristic optimization techniques, is employed to identify the creep parameters, since the mechanical responses to several levels of loading during firing processes involve all the non-mechanical and mechanical deformation of specimens simultaneously. The calculation results with the proposed constitutive equations are compared with the original experimental data to demonstrate the applicability for practical use of their function forms determined by the proposed strategy.
Anisotropic Damage Constitutive Law Derived from Atomic Separation Process on Cleavage Plane

Shintaku, Yuichi, Terada, Kenjiro, Tsutsumi, Seiichiro

Proceedings of the International Symposium on Visualization in Joining & Welding Science through Advanced Measurements and Simulation (Visual-JW 2016)　2016/10
Numerical-analysis-aided probablistic tsunami hazard evaluation using response surface Peer-reviewed

Takuma KOTANI, Shinsuke TAKASE, Shuji MORIGUCHI, Kenjiro TERADA, Yo FUKUTANI, Yu OTAKE, Kazuya NOJIMA, Masaaki SAKURABA

Journal of Applied Mechanics JSCE　72　(1)　58-69　2016/09/20
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.72.58 　

eISSN： 2185-4661
2D-3D hybrid stabilized finite element method for tsunami runup simulations Peer-reviewed

S. Takase, S. Moriguchi, K. Terada, J. Kato, T. Kyoya, K. Kashiyama, T. Kotani

COMPUTATIONAL MECHANICS　58　(3)　411-422　2016/09

DOI： 10.1007/s00466-016-1300-4 　

ISSN： 0178-7675

eISSN： 1432-0924
Optimum design of lattice structures based on continuum expression using micropolar continuum theory Peer-reviewed

Ayami SATO, Takayuki YAMADA, Kazuhiro IZUI, Shinji NISHIWAK, Kenjiro TERADA

Transactions of the JSME (in Japanese)　82　(840)　16-00171-00171　2016/07/25
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/transjsme.16-00171 　

eISSN： 2187-9761
Rheological constitutive model for thermoplastic resin based on viscoplastic-viscoelastic multiplicative decomposition of deformation gradient Peer-reviewed

Seishiro MATSUBARA, Kenjiro TERADA

Transactions of the JSME (in Japanese)　82　(839)　16-00060-00060-16-00060　2016/07/25
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/transjsme.16-00060 　

ISSN： 2187-9761

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We propose a rheology-based viscoelastic-viscoplastic constitutive model in which the deformation gradient is mutiplicatively decomposed into viscoelastic and viscoplastic components. The viscoelastic and viscoplastic rheology elements are connected in series, and the stress is determined only in the former element, which is modified by the back stress introduced in the latter one to represent the hardening due to orientation of molecular chains. The standard generalized Maxwell model is used to characterize the viscoelastic material behavior at small or moderate strain regime, while a proven finite strain viscoplastic model is employed to realize the transient creep deformations due to frictional resistance of molecular chains. After identifying the material parameters with reference to experimental data and verifying the fundamental performance of the proposed model in reproducing typical material behavior of resin, we carry out two kinds of numerical analyses for simple structures to demonstrate its applicability for practical use.
Identification of Hill's anisotropic parameters for reinforced plastics based on numerical material test results, Peer-reviewed

Koji YAMAMOTO, Norio HIRAYAMA, Kenjiro TERADA

Transactions of the JSME (in Japanese)　82　(840)　16-00056-00056-16-00056　2016/07/13
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/transjsme.16-00056 　

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A parameter identification issue for Hill's orthotropic model to characterize plastic and creep properties of reinforced plastics is revisited on the premise of the practical use of the numerical material testing (NMT) in decoupled multiscale analyses based on homogenization theory. Specifically, the use of optimization methods is suggested to determine the Hill's constants that represent elastic limits followed by plastic flows in anisotropic plasticity and stress-relaxation in anisotropic creep. To examine the effectiveness of the present strategy, NMTs are conducted on three separate periodic microstructures (unit cels) to obtain the macroscopic stress-strain or time-creep-strain curves and the particle swarm optimization (PSO) algorithm is employed for parameter identification. In each of the unit cells, polyamide and epoxy resins, which are assumed to respectively exhibit plastic and creep deformations, are selected for matrix phases, while carbon is taken as a reinforcing material in unidirectional-fiber, plain-weave-fiber and particulate-dispersion reinforced plastics. During the course of the examination, we also discuss the implication of the ratios of orthotropic elastic constants in the determination of Hill's constants for the creep model in terms of the relaxation spectrums in the directions of material axes.
An isotropic damage model based on fracture mechanics for concrete Peer-reviewed

Mao Kurumatani, Kenjiro Terada, Junji Kato, Takashi Kyoya, Kazuo Kashiyama

ENGINEERING FRACTURE MECHANICS　155　49-66　2016/04

DOI： 10.1016/j.engfracmech.2016.01.020 　

ISSN： 0013-7944

eISSN： 1873-7315
Cohesive-force embedded damage model and its application to crack propagation analyses Peer-reviewed

Yuichi Shintaku, Kenjiro Terada

Transactions of the Japan Society for Computational Engineering and Science　2016　2016/03/23
Publisher: Japan Society for Computational Engineering and Science
DOI： 10.11421/jsces.2016.20160011 　

ISSN： 1347-8826
Isogeometric analysis method for heterogeneous periodic microstructures Peer-reviewed

Seishiro Matsubara, Kenjiro Terada, Fumio Fujii

Transactions of the Japan Society for Computational Engineering and Science　2016　2016/03/23
Publisher: Japan Society for Computational Engineering and Science
DOI： 10.11421/jsces.2016.20160010 　

ISSN： 1347-8826
3D fracture simulation of reinforced concrete based on fracture mechanics for concrete and its performance assessment Peer-reviewed

Mao Kurumatani, Yuki Nemoto, Yuto Soma, Kenjiro Terada

Transactions of the Japan Society for Computational Engineering and Science　2016　2016/02/12
Publisher: Japan Society for Computational Engineering and Science
DOI： 10.11421/jsces.2016.20160004 　

ISSN： 1347-8826
逆均質化法を用いた微細亀裂分布の同定 Peer-reviewed

加藤準治, 河西亮輔, 京谷孝史, 寺田賢二郎

土木学会論文集A2（応用力学）　72　(1)　27-37　2016/02
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.72.27 　

ISSN： 2185-4661

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Detection of micro-cracks is very important to lengthen the lifetime of structures because micro-crack is a signal of initiation and growth of deterioration of materials and eventually degrades the mechanical performance of structures. However, no practically useful non-destructive testing device for large scale structures can capture the essential micro-crack for large structures in reality. In the meanwhile, nowadays, non-destructive testing simulation is also gaining attention. The term, non-destructive testing simulation, means a numerical testing for crack inspection applying computational mechanics. The present study proposes a method to determine micro-crack topology giving an equivalent homogenized macro-stiffness tensor to the prescribed anisotropic material stiffness tensor by applying an inverse-homogenization method. We demonstrate the accuracy of the evaluation of the proposed method in terms of a series of numerical simulations.
防潮林の減災特性評価を目的としたマルチスケール数値実験 Peer-reviewed

野村怜佳, 高瀬慎介, 寺田賢二郎, 森口周二

土木学会論文集A2（応用力学）　71　(2)　I_193-I_201　2016/02
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.71.I_193 　

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We propose a method of multiscale numerical experiments for evaluating disaster-reductoin characteristics of tide-protection forest against tsunami energy. To conduct the experiments in a hierarchical way, a tide-protection forest is stratified into three spatial scales; the branch-scale is the smallest, the forest-scale is the largest and the tree-scale is intermediate. Tide-Protection Forest is assumed to be porous media and we identify its porous term as reduction characteristics. With the help of the stabilized finite element method, several cases of lower-scale analyses are carried out with different initial and boundary conditions to construct a response surface of the overall resistances at the upper-scale. Thus, with this information about the porous medium's characteristics, a whole costal region can be a analysis target with relatively low computational cost to make a risk assessment for structures behind the forest.
複合厚板における断面構造のトポロジー最適化 Peer-reviewed

西紳之介, 寺田賢二郎, 加藤準治

土木学会論文集A2（応用力学）　71　(2)　I_245-I_254　2016/02
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.71.I_245 　

ISSN： 2185-4661

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The present study proposes a method of topology optimization of microstructures (in-plane unit cell) that maximizes the overall mechanical performance of composite plates. The proposed method hinges on the method of numerical plate testing for two-scale composite plate model, in which thick plate theory is employed at maco-scale and 3D solids are assumed at the micro-scale. Since the macroscopic generalized strain and stress are respectively related to the microscopic strain and stress distributed in the unit cell, the homogenizad plate stiffness approriately reflects the geometrical feature of microstructures. Several optimized topologies a maximeze the macroscopic stiffness are presented to demonstrate the capability of the proposed method.
熱可塑性樹脂の発熱現象を考慮した粘弾性・粘塑性複合構成則 Peer-reviewed

松原成志朗, 寺田賢二郎

土木学会論文集A2（応用力学）　71　(2)　I_509-I_520　2016/02
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.71.I_509 　

ISSN： 2185-4661

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We propose a rheology-based viscoelastic-viscoplastic constitutive model that takes into account the self-heating phenomenon of thermoplastic resin. Different kinds of hyperelastic constitutive laws are used for the viscoelastic and viscopelastic rheological elements. A generalized Maxwell model is used to characterize the viscoelastic material behavior at small or moderate strain regime, while a finite strain viscoplastic model is employed to transient creep deformations due to frictional resistance of molecular chains. Also, back stress is introduced to represent the hardening due to orientation of molecular chains. After verifying the fundamental performance of the proposed model in reproducing typical material behavior of resin, we carry out several numerical analyses for simple structures to demonstrate its applicability for practical use.
構造物の破壊を考慮した有限被覆法に基づく構造流体連成解析 Peer-reviewed

高瀬慎介, 森口周二, 寺田賢二郎, 小山直輝, 金子賢治, 車谷麻緒, 加藤準治, 京谷孝史

土木学会論文集A2（応用力学）　71　(2)　I_203-I_212　2016/02
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.71.I_203 　

ISSN： 2185-4661

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This paper presents stabilized finite cover based fluid-structure interaction analysis including fracture of structure. The fracture of structure and the contact of structure uses the discrete element method using Cohesive model. The stabilized method based on SUPG/PSPG methods are employed to solve the incompressible Navier-Stokes equation. Since the physical domain is defined independently of the mathematical domain in the finite cover method, the physical boundaries of the structure are represented explicitly in a spatially fixed mesh so that the continuity condition can be imposed directly on the actual interface within the framework of Eulerian approach, and the continuity conditions of velocity and stress vectors at the interface are imposed with the penalty method. Several numerical examples are presented to demonstrate the validity and efficiency of the proposed fluid-structure interaction method.
EFFECTS OF PARTICLE SIZE AND PARTICLE SHAPE IN FLOW SIMULATIONS OF DRY SAND USING DEM Peer-reviewed

森口周二, 蛭間雄大, 高瀬慎介, 寺田賢二郎

土木学会論文集A2（応用力学）　71　(2)　I_587-I_594　2016/02
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.71.I_587 　

ISSN： 2185-4661

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In order to investigate effects of particle size and particle shape in DEM simulations, a series of simulations of a model test using dry sand were carried out. By analyzing the simulated results, following findings were obtained. Non-spherical particles can describe flow behavior of sand much better than spherical particles, and it is possible to describe the flow behavior even if some bigger non-spherical particles are used in the simulation. It is also found that considering particle shape is important to describe the flow behavior but degree of the shape is not sensitive factor.
Multi-scale topology optimization for hyperelastic composites applying a decoupling multi-scale analysis Peer-reviewed

Junji KATO, Daishun YACHI, Shunsuke NISHIZAWA, Shinsuke TAKASE, Kenjiro TERADA, Takashi KYOYA

Transactions of the Japan Society for Computational Engineering and Science　p.20160001　2016/01/18

DOI： 10.11421/jsces.2016.20160001 　
Numerical plate testing for linear two-scale analyses of composite plates with in-plane periodicity Peer-reviewed

Kenjiro Terada, Norio Hirayama, Koji Yamamoto, Mayu Muramatsu, Seishiro Matsubara, Shin-nosuke Nishi

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING　105　(2)　111-137　2016/01

DOI： 10.1002/nme.4970 　

ISSN： 0029-5981

eISSN： 1097-0207
個別要素法による落石の確率論的危険度評価 Peer-reviewed

Shuji MORIGUCHI, Yu OTAKE, Shinsuke TAKASE, Kenjiro TERADA, Yuji KOSAKA, Masaru HORIUCHI, Kazuhide SAWADA, Atsushi YASHIMA

Japanese Geotechnical Journal　10　(4)　503-515　2015/12/31
Publisher: The Japanese Geotechnical Society
DOI： 10.3208/jgs.10.503 　

eISSN： 1880-6341
A PREDICTION MODEL OF STEEL CORROSION IN CONCRETE BASED ON REACTION-DIFFUSION EQUATION Peer-reviewed

Takashi USHIDA, Kiwamu TSUNO, Takashi NAKAYAMA, Shinsuke TAKASE, Kenjiro TERADA, Takashi KYOYA

, 土木学会論文集A2（応用力学）　71　(1)　34-45　2015/11/20

DOI： 10.2208/jscejam.71.34 　
Topology optimization of microstructures for hyperelastic composites based on a decoupling multi-scale analysis Peer-reviewed

Junji KATO, Daishun YACHI, Shunsuke NISHIZAWA, Shinsuke TAKASE, Kenjiro TERADA, Takashi KYOYA

Transactions of the Japan Society for Computational Engineering and Science　p.20150014　20150014-20150014　2015/11/06
Publisher: JAPAN SOCIETY FOR COMPUTATIONAL ENGINEERING AND SCIENCE
DOI： 10.11421/jsces.2015.20150014 　

ISSN： 1347-8826

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The present study proposes topology optimization for microstructure of two-phase composite considering hyperelasticity to minimize the end compliance of the macrostructure based on a multi-scale analysis. In general the structural behavior of macrostructure depends on the geometric properties of the microstructure. In other words, optimizing microstructure is an effectual way to improve the macroscopic structural performance applying a multi-scale analysis. However, it needs unrealistic computational costs when structural optimization with nonlinear structural response based on the conventional micro-macro coupling multi-scale analysis is considered. The present study challenges to make it possible to solve the problem by introducing a so-called decoupling multi-scale analysis assuming hyperelasticity.
Characterization of time-varying macroscopic electro-chemo-mechanical behavior of SOFC subjected to Ni-sintering in cermet microstructures Peer-reviewed

M. u Muramatsu, K. Terada, T. Kawada, K. Yashiro, K. Takahashi, S. Takase

COMPUTATIONAL MECHANICS　56　(4)　653-676　2015/10

DOI： 10.1007/s00466-015-1193-7 　

ISSN： 0178-7675

eISSN： 1432-0924
加工誘起変態を考慮した結晶塑性FE解析による局所応力評価

堤成一郎, Fincato Riccardo, 寺田賢二郎

日本鉄鋼協会シンポジウム「ベイナイト鋼脆性破壊の微視的機構とそのモデル化」　13-20　2015/09
Analytical sensitivity in topology optimization for elastoplastic composites Peer-reviewed

Junji Kato, Hiroya Hoshiba, Shinsuke Takase, Kenjiro Terada, Takashi Kyoya

STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION　52　(3)　507-526　2015/09

DOI： 10.1007/s00158-015-1246-8 　

ISSN： 1615-147X

eISSN： 1615-1488
Cohesive Crack Model to Reflect Local Chemical Action at Grain and Its Boundaries in Polycrystalline Metals Peer-reviewed

Yuichi Shintaku, Mayu Muramatsu, Shinsuke Takase, Seiichiro Tsutsumi, Kenjiro Terada

Quarterly J. Japan Welding Soc.　33　(2)　152s-155s　2015/06

DOI： 10.2207/qjjws.33.152s 　
A Crystal Plasticity FE Analysis Considering Mechanically Induced Martensitic Phase Transformation Peer-reviewed

Seiichiro Tsutsumi, Riccardo Fincato, Kazushi Ueda, Kenjiro Terada

Quarterly J. Japan Welding Soc.　33　(2)　102s-106s　2015/04

DOI： 10.2207/qjjws.33.102s 　

ISSN： 0288-4771
斜面近傍に位置する逆T字型送電鉄塔基礎の引揚支持力解析 Peer-reviewed

山川優樹, 溝江弘樹, 千田大, 戸田丈, 池田清宏, 田村洋, 寺田賢二郎

土木学会論文集C（地圏工学）　71　(1)　1-13　2015/02/20
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejge.71.1 　

ISSN： 2185-6516

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The conventional formula, the so-called logarithmic spiral equation, for uplift capacity of enlarged base anchor foundation for transmission towers is capable of evaluating accurately the uplift capacity in horizontal grounds, and thus is widely used in engineering practice. However, in the evaluation of the uplift capacity in inclined grounds or other complex embedment conditions, control of minimum embedment depth or conical soil volume to insure a sufficient overburden weight, or some empirical approach, is employed. This paper examines the uplift capacity of anchor foundation embedded in a slope crest. For this purpose, the three-dimensional elastoplastic finite element analysis is utilized. The effect of the distance from the edge of slope crest on the uplift capacity is investigated for different slope angles. The analysis result shows that, if the edge distance is less than a certain value, the uplift capacity decreases significantly with a decrease in the edge distance. It is also found that the uplift capacity decreases nonlinearly with an increase in the slope angles, and it shows a larger decrease as the edge distance is smaller.
フェーズフィールド法によるミクロ構造トポロジー最適化の基礎的研究 Peer-reviewed

加藤準治, 加茂純宜, 高瀬慎介, 森口周二, 車谷麻緒, 寺田賢二郎, 京谷孝史

土木学会論文集 A2(応用力学)　70　(2)　I_173-I_183　2015/02/20
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.70.I_173 　

ISSN： 2185-4661

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It is well known that the mechanical behavior of material mainly depends on the geometric properties of the microstructure, such as material distribution, shape or size of the material. It is said that it will be possible to maximize the mechanical performance of a macro-structure, if 'types or kinds of materials to be mixed or the combinations thereof' are optimized and 'the geometric properties of micro-structure' are optimized. For this reason, the authors have developed topology optimization of microstructure using the general finite element method as a numerical approach. However, the general finite element mesh is not necessary appropriate to express the complicated real material distribution of microstructure and furthermore depends considerably on the initial value of some parameters. Thus, the present study applies a new approach, the phase-field method, to express the complicated topology of microstructure and introduces the formulation to maximize the stiffness of the microstructure with a prescribed material volume under linear elastic regime. For the fundamental research, we firstly start from investigation of the initial value dependency of the present method on the final optimization solution by making use of a series of numerical examples.
安定化有限要素法を用いた2D-3Dハイブリット手法による津波解析 Peer-reviewed

高瀬慎介, 加藤準治, 森口周二, 寺田賢二郎, 京谷孝史, 野島和也, 桜庭雅明, 樫山和男

土木学会論文集 A2(応用力学)　70　(2)　I_307-I_315　2015/02/20
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.70.I_307 　

ISSN： 2185-4661

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This paper presents a 2D-3D hybrid stabilized finite element method that enables us to analyze both tsunami offshore propagation and runup in urban areas with high accuracy and relatively low computational costs. The shallow water equations are employed for 2D simulation of the offshore flow in a global oceanic area, while the incompressible Navier-Stokes equations are used to analyze 3D flow behavior in a local urban area. The SUPG method is commonly applied to stabilize both the 2D and 3D FE discretized equations, and the VOF method is used to capture the 3D free-surface flow. Meshes for 2D and 3D simulations are generated independently of each other and the method of multiple-point constraint is applied to impose the continuity conditions of flow velocities and pressures at the interface between the 2D and 3D meshes of different topologies. Several numerical examples are presented to demonstrate the performance and efficiency of the proposed hybrid method.
弾塑性材料の繰り返し載荷を考慮したマルチフェーズトポロジー最適化および解析的感度の精度検証 Peer-reviewed

干場大也, 加藤準治, 高瀬慎介, 寺田賢二郎, 京谷孝史

，土木学会論文集 A2(応用力学)　70　(2)　I_317-I_328　2015/02/20
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.70.I_317 　

ISSN： 2185-4661

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The present study introduces a derivation of analytical sensitivity for topology optimization of composites considering elastoplastic deformation to maximize the energy absorption capacity under a prescribed material volume. For optimization applying a gradient-based method, the accuracy of sensitivities is critical to obtain a reliable optimization result, especially in the vicinity of undifferentiable points such as yield points and unloading starting points in the stress-strain curve. In the previous authors' work¹⁾, it is verified that the proposed analytical sensitivity can provide highly accurate sensitivities over yield points under loading situation. In this study, as an extension to a more realistic loading situation, we demonstrate topology optimization under cyclic loading condition and verify the accuracy of the proposed sensitivity approach by comparing with that evaluated from the finite difference approach.
複合板の線形マルチスケール解析のための数値平板試験 Peer-reviewed

Kenjiro TERADA, Norio HIRAYAMA, Koji YAMAMOTO, Seishiro MATSUBARA

Transactions of the Japan Society for Computational Engineering and Science　p.20150001　2015/01/23

DOI： 10.11421/jsces.2015.20150001 　
Two-scale assessment of tensile and compressive strengths of heterogeneous rock mass Peer-reviewed

K. Terada, T. Kyoya, T. Ishida, J. Kato, S. Moriguchi, S. Takase, S. Koumura

Computer Methods and Recent Advances in Geomechanics　1459-1464　2015
A method of numerical analyses for predicting corrosion-induced mechanical deterioration of RC structures Peer-reviewed

K. Terada, S. Takase, Y. Kudo, S. Nishi, J. Kato, T. Kyoya, T. Ushida, K. Tsuno, T. Nakayama

LIFE-CYCLE OF STRUCTURAL SYSTEMS: DESIGN, ASSESSMENT, MAINTENANCE AND MANAGEMENT　1757-1764　2015
Effects of grain size and grain shape in granular flow simulations Peer-reviewed

S. Moriguchi, K. Terada, J. Kato, S. Takase, T. Kyoya

Computer Methods and Recent Advances in Geomechanics　1453-1458　2015
Multiphase topology optimization of composites under elastoplastic behavior Peer-reviewed

J. Kato, H. Hoshiba, S. Takase, K. Terada, T. Kyoya

Structural and Multidisciplinary Optimization　2015
Local stress increase due to mechanically induced phase transformation predicted by a crystal FE analysis Peer-reviewed

S. Tsutsumi, R. Fincato, K. Terada, T. Ishida

MATERIALS TODAY-PROCEEDINGS　2　(3)　611-614　2015

DOI： 10.1016/j.matpr.2015.07.358 　

ISSN： 2214-7853
AN ELECTRO-CHEMO-MECHANICAL ANALYSIS OF SOLID OXIDE FUEL CELL CONSIDERING EVOLUTION OF MICROSTRUCTURE IN POROUS ELECTRODE USING PHASE-FIELD METHOD Peer-reviewed

M. Muramatsu, S. Takase, K. Yashiro, T. Kawada, K. Terada

Coupled Problems in Science and Engineering VI　614-624　2015
A MULTI-SCALE ELECTRO-CHEMO-MECHANICAL ANALYSIS OF SOLID OXIDE FUEL CELL CONSIDERING EVOLUTION OF MICROSTRUCTURE IN POROUS ELECTRODE Peer-reviewed

M. Muramatsu, S. Takase, K. Yashiro, T. Kawada, K. Terada

PROCEEDINGS OF THE 1ST PAN-AMERICAN CONGRESS ON COMPUTATIONAL MECHANICS AND XI ARGENTINE CONGRESS ON COMPUTATIONAL MECHANICS　215-224　2015
Electro-chemical potential analysis of zirconium based on the reaction-diffusion equations of oxygen ion and electron considering phase transformation Peer-reviewed

M. Muramatsu, H. Kishimoto, K. Yamaji, K. Yashiro, T. Kawada, K. Terada, H. Yokokawa

ECS Transactions　68　(1)　2363-2372　2015
Publisher: Electrochemical Society Inc.
DOI： 10.1149/06801.2363ecst 　

ISSN： 1938-6737 1938-5862

eISSN： 1938-6737
開削トンネルにおける調査データの分析と将来予測手法の検討 Peer-reviewed

牛田貴士, 仲山貴司, 津野究, 嶋本敬介, 焼田真司, 寺田賢二郎, 京谷孝史

土木学会論文集F1　71　(1)　41-53　2015
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejte.71.41 　

ISSN： 2185-6575

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In this paper, we have clarified the relationship between aging of subway cut-and-cover tunnels and rate of cracking that is caused by carbonation or chloride attack. First, field data analyses were carried out to characterize the material deterioration in the tunnels. Next, laboratory experiments were conducted to introduce a method of estimating the amount of corrosion products and the resulting expansion coefficient at the onset of cracking around a round steel. Finally, based on these findings, the statistical prediction method for material deteriorations was proposed and its usage in conjunction with numerical analyses was demonstrated. The proposed method is expected to be utilized for maintenance planning of tunnels, many of which were constructed about 40 years ago.
An analysis of fatigue crack propagation in pollycrystalline metals using cohesive zone model with damage variable Peer-reviewed

Yuichi SHINTAKU, Mayu MURAMATSU, Seiichiro TSUTSUMI, Kenjiro TERADA, Takashi KYOYA, Junji KATO, Shuji MORIGUCHI

Transactions of the Japan Society for Computational Engineering and Science　p.20140014　2014/10/10

DOI： 10.11421/jsces.2014.20140014 　
Accuracy validation of analytical sensitivity in topology optimization for elastoplastic composites Peer-reviewed

Junji KATO, Hiroya HOSHIBA, Shinsuke TAKASE, Kenjiro TERADA, Takashi KYOYA

Transactions of the Japan Society for Computational Engineering and Science　p.20140012　2014/09/29

DOI： 10.11421/jsces.2014.20140012 　
Applicability of micro-macro decoupling scheme to two-scale analysis of fiber-reinforced plastics Peer-reviewed

Kenjiro Terada, Norio Hirayama, Koji Yamamoto, Junji Kato, Takashi Kyoya, Seishiro Matsubara, Yusuke Arakawa, Yuta Ueno, Naohiro Miyanaga

ADVANCED COMPOSITE MATERIALS　23　(5-6)　421-450　2014/09

DOI： 10.1080/09243046.2014.915098 　

ISSN： 0924-3046

eISSN： 1568-5519
Simulation of compressive failure in quasi-brittle materials involving contact on crack interfaces Peer-reviewed

神野真弥, 車谷麻緒, 寺田賢二郎, 京谷孝史, 樫山和男

Transactions of the Japan Society for Computational Engineering and Science　p.20140006　20140006-20140006　2014/04/24
Publisher: JAPAN SOCIETY FOR COMPUTATIONAL ENGINEERING AND SCIENCE
DOI： 10.11421/jsces.2014.20140006 　

ISSN： 1347-8826

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This paper proposes a method for simulating compressive failure in quasi-brittle materials involving micro- or meso-scale contact on crack interfaces. The macroscopic compressive failure is assumed to be caused by tensile and shear fractures at micro-scale, both of whose traction-crack-opening behavior is represented by the cohesive crack model. The penalty method is employed to realize the frictional contact on cracked interfaces under compressive loading. First, the discrete micro-crack behavior is introduced to a finite element framework in consideration of material inhomogeneity of cement-based materials and by using penalty springs. Then, after verifying the basic performance for simulating fracture behavior involving tensile or shear cracks, we examine the role of the micro-scale frictional contact behavior on the compressive fracture behavior. Finally, a numerical example is presented to demonstrate the validity of the proposed method in comparison with the experimental result, reported in the literature, for the compressive fracture behavior in mortar and cement paste.
弾塑性・クリープ・損傷複合モデルによる繊維強化プラスチックの分離型マルチスケール解析 Peer-reviewed

松原成志朗, 荒川裕介, 加藤準治, 寺田賢二郎, 京谷孝史, 上野雄太, 宮永直弘, 平山紀夫, 山本晃司

計算工学会論文集　2014　p20140004　2014/04/15

DOI： 10.11421/jsces.2014.20140004 　
A Method for Two-Scale Analysis for Crack Propagation in Polycrystalline Metals

Yuichi Shintaku, Kenjiro Terada, Junji Kato, Takashi Kyoya, Shuji Moriguchi, Shinsuke Takase, Seiichiro Tsutsumi

Proc. COMPSAFE 2014　125-128　2014/04
Topology optimization of micro-structure for composites applying a decoupling multi-scale analysis Peer-reviewed

Junji Kato, Daishun Yachi, Kenjiro Terada, Takashi Kyoya

STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION　49　(4)　595-608　2014/04

DOI： 10.1007/s00158-013-0994-6 　

ISSN： 1615-147X

eISSN： 1615-1488
Layout design of rockbolts for natural ground reinforcement Peer-reviewed

Junji Kato, Keiichiro Ishii, Kenjiro Terada, Takashi Kyoya

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS　38　(3)　236-255　2014/02

DOI： 10.1002/nag.2202 　

ISSN： 0363-9061

eISSN： 1096-9853
Two-scale analysis of tensile and compressive strengths of alternate layers of inclined rock masses

T. Kyoya, T. Ishida, K. Terada, J. Kato, S. Moriguchi, S. Takase

ISRM International Symposium - 8th Asian Rock Mechanics Symposium, ARMS 2014　429-437　2014
Publisher: International Society for Rock Mechanics
De-coupled multi-scale analyses of fiber-reinforced composites by elastic-creep-damage combined model

Seishiro Matsubara, Yusuke Arakawa, Junji Kato, Kenjiro Terada, Takashi Kyoya, Yuta Ueno, Naohiro Miyanaga, Norio Hirayama, Kouji Yamamoto

Transactions of the Japan Society for Computational Engineering and Science　2014　2014
Publisher: Japan Society for Computational Engineering and Science
ISSN： 1347-8826
MULTI-SCALE CRACK PROPAGATION ANALYSIS FOR STRENGH ASSESSMENT OF POLYCRSTALINE MATERIALS Peer-reviewed

Y. Shintaku, K. Terada, J. Kato, T. Kyoya, S. Takase, S. Tsutsumi

11TH WORLD CONGRESS ON COMPUTATIONAL MECHANICS; 5TH EUROPEAN CONFERENCE ON COMPUTATIONAL MECHANICS; 6TH EUROPEAN CONFERENCE ON COMPUTATIONAL FLUID DYNAMICS, VOLS II - IV　1569-1580　2014
NUMERICAL EVALUATION OF TSUNAMI IMPACT FORCE ACTED ON A BRIDGE GIRDER DURING TSUNAMI BY USING A PARTICLE METHOD Peer-reviewed

Shoichi Tanabe, Mitsuteru Asai, Kenjiro Terada, Kazuo Kashiyama, Shuji Moriguchi, Mao Kurumatani

11TH WORLD CONGRESS ON COMPUTATIONAL MECHANICS; 5TH EUROPEAN CONFERENCE ON COMPUTATIONAL MECHANICS; 6TH EUROPEAN CONFERENCE ON COMPUTATIONAL FLUID DYNAMICS, VOLS II - IV　4066-4076　2014
Quantitative relationship between shape representation quality and calculation accuracy Peer-reviewed

TACHIBANA Ikkoh, MORIGUCHI Shuji, TERADA Kenjiro, TAKASE Shinsuke, KYOYA Takashi, KATO Jyunji

Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM))　70　(2)　I_519-I_530　2014
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.70.I_519 　

ISSN： 2185-4661

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In this study, the effect of shape representation in rockfall simulations using DEM was investigated. A model test and it's simulation were performed. In the simulation, differnt numerical models were prepared by changing shape representation to figure out a quantitative relationship between shape representation and calculation accuracy. Every simulations were done in the same condition as experiment, except the shape representation quality of calculation models. Two non-dimensional indexes, namely ESR and OR, were defined to enable quantification of the shape representation quality. Eventually, the relationship between the shape representation quality and the accuracy of DEM simulation were found through comparison of simulated data with experiment. Based on the results obtained in this study, the framework to enable quantitative design of calculation accuracy by controlling shape representation quality was proposed.
A method of two-scale analysis with micro-macro decoupling scheme: application to hyperelastic composite materials Peer-reviewed

K. Terada, J. Kato, N. Hirayama, T. Inugai, K. Yamamoto

COMPUTATIONAL MECHANICS　52　(5)　1199-1219　2013/11

DOI： 10.1007/s00466-013-0872-5 　

ISSN： 0178-7675

eISSN： 1432-0924
Identification of Ni-YSZ Anode Creep Property Using PSO for Multiscale Simulation Peer-reviewed

S. Watanabe, F. Iguchi, K. Sato, K. Yamamoto, T. Hashida, K. Terada, T. Kawada

SOLID OXIDE FUEL CELLS 13 (SOFC-XIII)　57　(1)　1379-1386　2013

DOI： 10.1149/05701.1379ecst 　

ISSN： 1938-5862
Analytical sensitivity analysis for decoupling multi-scale topology optimization of composites Peer-reviewed

Daishun Yachi, Junji Kato, Shinsuke Takase, Kenjiro Terada, Takashi Kyoya

Transactions of the Japan Society for Computational Engineering and Science　2013　p20130022　2013

DOI： 10.11421/jsces.2013.20130022 　

ISSN： 1347-8826
Deformation and strength characterization of Mg alloys with rolled crystallographic textures by crystal plasticity finite element method Peer-reviewed

Tomohiro Ishida, Shinpei Shibutani, Junji Kato, Kenjiro Terada, Takashi Kyoya, Daisuke Ando, Junichi Koike

Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A　79　(808)　1840-1851　2013
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.79.1840 　

ISSN： 0387-5008
An isotropic damage model based on fracture mechanics for concrete and its evaluation Peer-reviewed

Mao Kurumatani, Kenjiro Terada, Junji Kato, Takashi Kyoya, Kazuo Kashiyama

Transactions of the Japan Society for Computational Engineering and Science　2013　P20130015　2013

DOI： 10.11421/jsces.2013.20130015 　

ISSN： 1347-8826
破壊シミュレーションのための構造要素を用いた離散体解析法 Peer-reviewed

車谷麻緒, 寺田賢二郎, 京谷孝史, 加藤準治, 樫山和男

日本計算工学会論文集　2013　P20130010　2013

DOI： 10.11421/jsces.2013.20130010 　
マルチスケールトポロジー最適化手法の3次元構造問題への拡張 Peer-reviewed

加藤準治, 谷地大舜, 高瀬慎介, 寺田賢二郎, 京谷孝史

応用力学論文集, 土木学会　16　I_133-I_144　2013

DOI： 10.2208/jscejam.69.I_133 　
骨材の幾何学的非均質性に着目したコンクリートの圧縮破壊シミュレーション Peer-reviewed

車谷麻緒, 神野真弥, 寺田賢二郎

応用力学論文集, 土木学会　16　I_115-I_123　2013

DOI： 10.2208/jscejam.69.I_115 　
SOFC構成材料の物理化学的・機械的特性とセル・スタックの信頼性

川田達也, 渡辺智, 坂本正, 尾澤伸樹, 佐藤一永, 橋田俊之, 宇根本篤, 八代圭司, 雨澤浩史, 水崎純一郎, 井口史匡, 橋本真一, 湯上浩雄, 寺田賢二郎

第21回SOFC研究発表会予稿集　28-34　2012/12
SOFCの信頼性と構成材料の物理化学的・機械的特性 Peer-reviewed

川田達也, 渡辺智, 坂本正, 井口史匡, 佐藤一永, 橋本真一, 尾澤伸樹, 島崎智実, 寺田賢二郎, 八代圭司, 雨澤浩史, 橋田俊之, 久保百司, 湯上浩雄, 水崎純一郎

水素エネルギーシステム　37　(2)　101-106　2012/06/30
Effect of rolling reduction on mechanical properties of copper plate

Takashi Kuboki, Toru Matsumoto, Yingjun Jin, Kenjiro Terada

Steel Research International　SPL. ISSUE　99-102　2012
Publisher: Wiley-VCH Verlag
ISSN： 1611-3683
Strength evaluation of discontinuous rock mass by multi-scale limit load analysis Peer-reviewed

J. Jung, J. Kato, K. Terada, T. Kyoya

HARMONISING ROCK ENGINEERING AND THE ENVIRONMENT　663-666　2012
Evaluation of Strength Characteristics of Fissured Rock Mass by a Multi-scale Limit Load Analysis Peer-reviewed

Jahe Jung, Junji Kato, Kenjiro Terada, Takashi Kyoya

7th Asian Rock Mechanics Symposium (ARMS7)　2012
A new constitutive model for crystal plasticity with deformation twinning Peer-reviewed

Ishida, T, Shibutani, S, Kato, J, Terada, K, Kyoya, T, Ando, D, Koike, J

Transactions of the Japan Society for Computational Engineering and Science　2012　2　2012

eISSN： 1347-8826
Simulation of ultrasonic and electromagnetic wave propagation for nondestructive testing of concrete using image–based FIT Peer-reviewed

Kazuyuki NAKAHATA, Kenjiro TERADA, Takashi KYOYA, Makoto TSUKINO, Keizo ISHII

Journal of Computational Science and Technology　6　(1)　28-37　2012
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jcst.6.28 　

ISSN： 1881-6894

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Presently, ultrasonic and electromagnetic waves are often used for the quantitative nondestructive testing of concrete. The evaluation of material deterioration and detection of defects in concrete are carried out using ultrasonic waves. On the other hand, the positions of reinforced bars can be reconstructed by using electromagnetic waves. In order to gain a better understanding of ultrasonic and electromagnetic waves in concrete, it is useful to model the wave propagation and scattering process explicitly in the time domain. This study presents a technique for numerical time domain modelings of ultrasonic and electromagnetic waves. Our simulation tool is based on a combination of the finite integration technique (FIT) and an image-based modeling approach. The FIT is a grid-based spatial discretization method that works in conjunction with a leap-frog-type explicit scheme. In the image-based modeling approach, geometries of concrete are determined using a digital image, e.g., a cross-sectional image or CT data. Then the processed pixel or voxel data are directly fed into the FIT. We demonstrate simulations of the contact ultrasonic method and electromagnetic radar method for concrete. The utility of the image-based FIT is validated with experimentally measured data.
一般化有限要素法による不連続性の近似に関する比較考察 Peer-reviewed

車谷麻緒, 寺田賢二郎

応用力学論文集，土木学会　15　I_129-I_138　2012

DOI： 10.2208/jscejam.68.I_129 　
複合材料のマクロ構造挙動を考慮したミクロ構造トポロジー最適化 Peer-reviewed

加藤準治, 寺田賢二郎, 京谷孝史

応用力学論文集，土木学会　15　I_279-I_290　2012

DOI： 10.2208/jscejam.68.I_279 　
六方晶金属の結晶塑性・変形双晶構成モデル Peer-reviewed

石田智広, 渋谷慎兵, 加藤準治, 寺田賢二郎, 京谷孝史, 安藤大輔, 小池淳一

計算工学会論文集　2012　P20120014　2012
多孔質微細構造の力学的作用を考慮した焼結シミュレーションによるマクロ物性予測 Peer-reviewed

笹川崇, 高橋健, 寺田賢二郎, 川田達也

計算工学会論文集　2012　P20120004　2012
SOFCの機械的信頼性・耐久性向上に向けたその場観察手法開発

井口史匡, 佐藤一永, 島崎知実, 尾澤伸樹, 寺田賢二郎, 橋田俊之, 湯上浩雄, 八代圭司, 坂本正, 宇根本篤, 水崎純一郎, 橋本真一, 渡辺智, 雨澤浩史, 川田達也

第20回SOFC研究発表会予稿集　144-147　2011/12
A method of global-local analyses of structures involving local heterogeneities and propagating cracks Peer-reviewed

Mao Kurumatani, Kenjiro Terada

STRUCTURAL ENGINEERING AND MECHANICS　38　(4)　529-547　2011/05

DOI： 10.12989/sem.2011.38.4.529 　

ISSN： 1225-4568
Application of Homogenization Method Considering Crystal Plasticity for Prediction of Mechanical Properties for Copper and Low Carbon Steel

Takuya Sueoka, Takashi Kuboki, Makoto Murata, Kouichi Kuroda, Kenjiro Terada

COMPUTATIONAL PLASTICITY XI: FUNDAMENTALS AND APPLICATIONS　603-609　2011
Prediction of sound absorption coefficients of poroelastic media by the homogenization method Peer-reviewed

T. Yamamoto, S. Maruyama, K. Terada, K. Izui, S. Nishiwaki

40th International Congress and Exposition on Noise Control Engineering 2011, INTER-NOISE 2011　3　1989-1996　2011
Multiscale Simulation of Electro-Chemo-Mechanical Coupling Behavior of PEN Structure under SOFC Operation Peer-reviewed

K. Terada, T. Kawada, K. Sato, F. Iguchi, K. Yashiro, K. Amezawa, M. Kubo, H. Yugami, T. Hashida, J. Mizusaki, H. Watanabe, T. Sasagawa, H. Aoyagi

SOLID OXIDE FUEL CELLS 12 (SOFC XII)　35　(1)　923-933　2011

DOI： 10.1149/1.3570073 　

ISSN： 1938-5862
A generalized macroscopic model for sound-absorbing poroelastic media using the homogenization method Peer-reviewed

T. Yamamoto, S. Maruyama, K. Terada, K. Izui, S. Nishiwaki

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING　200　(1-4)　251-264　2011

DOI： 10.1016/j.cma.2010.08.009 　

ISSN： 0045-7825
有限被覆法に基づく自由表面を有する流体・構造連成解析手法の構築 Peer-reviewed

中村正人, 高瀬慎介, 樫山和男, 寺田賢二郎, 車谷麻緒

土木学会論文集A2（応用力学）　67　(2)　2011

DOI： 10.2208/jscejam.67.I_199 　
多層材料レイアウト最適化手法のロックボルト支保工への適用性検証 Peer-reviewed

加藤準治, 石井慶一郎, 寺田賢二郎, 京谷孝史

土木学会論文集A2（応用力学）　67　(2)　2011

DOI： 10.2208/jscejam.67.I_107 　
損傷を受ける繊維複合材料の繊維形状最適化 Peer-reviewed

加藤準治, Ekkehard RAMM, 寺田賢二郎, 京谷孝史

土木学会論文集A2（応用力学）　67　(1)　54-68　2011

DOI： 10.2208/jscejam.67.54 　
繊維複合材料のひずみ軟化を考慮した多層材料最適化手法の提案 Peer-reviewed

加藤準治, Ekkehard RAMM, 寺田賢二郎, 京谷孝史

土木学会論文集A2（応用力学）　67　(1)　39-53　2011

DOI： 10.2208/jscejam.67.39 　
X-FEMによる非均質材料の波動伝搬解析に関する基礎的研究 Peer-reviewed

車谷麻緒, 寺田賢二郎, 京谷孝史

土木学会論文集A2（応用力学）　67　(1)　69-81　2011

DOI： 10.2208/jscejam.67.69 　
Equivalent properties of sound absorbing poroelastic material using the homogenization Peer-reviewed

T. Yamamoto, S. Maruyama, K. Izui, S. Nishiwaki, K. Terada

Transactions of the Japan Society of Mechanical Engineers, Series C　77　(773)　75-88　2011
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaic.77.75 　

ISSN： 0387-5024

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In this paper we propose a new method to derive macroscopic equivalent properties of sound absorbing poroelastic material using the homogenization method. Assuming that the microscopic geometry of the poroelastic material is periodic, this method directly provides a macroscopic elastic tensor for the solid phase, an equivalent density and a bulk modulus for the fluid phase. In the derivation of the macroscopic properties, we perform multiphysics analysis of several phenomena arising in the sound absorption by the poroelastic material, namely, elastic motion of the solid phase, compressible viscous fluid flow in the fluid phase, temperature distribution in the fluid phase, and coupled effects between solid and fluid phases. The equivalent density is obtained by averaging the characteristic function of the fluid flow, and the equivalent bulk modulus is calculated by averaging the characteristic function of the temperature distribution. Several numerical models with simple microscopic geometries are employed to compare the macroscopic properties represented in the numerical solutions obtained using the proposed method with solutions obtained analytically. We demonstrate that the proposed method can provide solutions with sufficient accuracy and that the solutions converge to analytically obtained solutions as the value of the discretization parameter used in the numerical models is made smaller.
Study for evaluating fracture-toughness in quasi-brittle materials based on the energy valance of structures Peer-reviewed

Mao KURUMATANI, Tatsuya YUMOTO, Kenjiro TERADA, Takashi KYOYA, Mitsuyoshi AKIYAMA

JSCE Journal of Applied Mechanics　13　313-322　2010/08
Strength evaluation of ultra high-strength cement paste by crack propagation analysis of microstructure Peer-reviewed

Takashi SASAGAWA, Mao KURUMATANI, Kenjiro TERADA, Tetsushi KANDA, Jin-Hwan JEON, Haruki MOMOSE

JSCE Journal of Applied Mechanics　13　283-291　2010/08
Two-scale diffusion-deformation coupling model for material deterioration involving micro-crack propagation Peer-reviewed

Kenjiro Terada, Mao Kurumatani

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING　83　(4)　426-451　2010/07

DOI： 10.1002/nme.2835 　

ISSN： 0029-5981
A method of two-scale thermo-mechanical analysis for porous solids with micro-scale heat transfer Peer-reviewed

K. Terada, M. Kurumatani, T. Ushida, N. Kikuchi

COMPUTATIONAL MECHANICS　46　(2)　269-285　2010/07

DOI： 10.1007/s00466-009-0400-9 　

ISSN： 0178-7675
Verification of multi-scale analysis for partially improved grounds by centrifugal experiments and its application to in-situ load-settlement problem Peer-reviewed

Akira Ishikawa, Kenjiro Terada, Takashi Kyoya, Yasuhiro Shamoto

Journals of the Japan Society of Civil Engineers　66　(2)　332-341　2010/05

DOI： 10.2208/jscejc.66.332 　
Multis-scale analysis method for partially impropved grounds by using a newly proposed nonlinear elastic constitutive model Peer-reviewed

Akira Ishikawa, Kenjiro Terada, Takashi Kyoya, Yasuhiro Shamoto

Journals of the Japan Society of Civil Engineers　66　(1)　145-155　2010/03

DOI： 10.2208/jscejc.66.145 　
EULERIAN FINITE COVER METHOD FOR SOLID DYNAMICS Peer-reviewed

Shigenobu Okazawa, Hideyuki Terasawa, Mao Kurumatani, Kenjiro Terada, Kazuo Kashiyama

INTERNATIONAL JOURNAL OF COMPUTATIONAL METHODS　7　(1)　33-54　2010/03

DOI： 10.1142/S0219876210002052 　

ISSN： 0219-8762
A method of predicting macroscopic yield strength of polycrystalline metals subjected to plastic forming by micro-macro de-coupling scheme Peer-reviewed

I. Watanabe, K. Terada

INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES　52　(2)　343-355　2010/02

DOI： 10.1016/j.ijmecsci.2009.10.006 　

ISSN： 0020-7403
An analysis of dynamic tensile fracture in concrete under high strain rate Peer-reviewed

M. Kurumatani, S. Iwata, K. Terada, S. Okazawa, K. Kashiyama

Analysis of Discontinuous Deformation: New Developments and Applications　555-562　2010

DOI： 10.3850/9789810844554-0041 　
A multi-scale analysis method for partially improved ground and its experimental verification Peer-reviewed

A. Ishikawa, Y. Shamoto, K. Terada, T. Kyoya

PHYSICAL MODELLING IN GEOTECHNICS, VOLS. 1 AND 2　1333-1338　2010
微細ひび割れの形成・連結・開閉に起因した準脆性材料の破壊進行メカニズム Peer-reviewed

車谷麻緒, 寺田賢二郎, 竹内則雄

土木学会論文集A2　66　(3)　505-515　2010

DOI： 10.2208/jsceja.66.505 　
A model for sound-absorbing poroelastic material using multiscale analysis Peer-reviewed

Takashi Yamamoto, Shinichi Maruyama, Kazuhiro Izui, Shinji Nishiwaki, Kenjiro Terada

Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C　76　(768)　2039-2048　2010
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaic.76.2039 　

ISSN： 0387-5024
An Evaluation Method of Macroscopic Yield Strength for Polycrystalline Metals Subjected to Plastic Forming by Micro-Macro Decoupling Analysis Peer-reviewed

WATANABE Ikumu, TERADA Kenjiro

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A　76　(766)　752-760　2010
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.76.752 　

ISSN： 0387-5008

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We introduce a method of predicting macroscopic yield strength of polycrystalline metals subjected to plastic forming by applying the micro-macro decoupling analysis method. The macroscopic plastic forming problem is assumed to be a three-stage forming process and is simulated with a single finite element in this study. At the same time, a polycrystalline aggregate composed of several crystal grains is adopted as a microstructure and is regarded as a numerical specimen for numerical material tests based on the homogenization theory. After simulating the macro-scale forming process with macroscopic approximate constitutive model, we apply the resulting macroscopic deformation histories to the microstrcutre to obtain the numerical specimen that enables us to evaluate the post-forming yield strengths. By performing the equivalent micro-macro coupling analysis and comparing the results with those by the coupling method, we demonstrate the capability of the proposed method in predicting the anisotropy in the macroscopic yield strength.
Meos-scale dynamic fracture simulations of concrete in tension under high strain-rate Peer-reviewed

Satoshi Iwata, Mao Kurumatani, Kenjiro Terada, Shigenobu Okazawa, Kazuo Kashiyama

JSCE Journal of Applied Mechanics　12　311-319　2009/08
Publisher:
ISSN： 1345-9139
A study of large deformation solid dynamics using Eulerian finite cover method Peer-reviewed

Shigenobu Okazawa, Mao Kurumatani, Hideyuki Terasawa, Kenjiro Terada, Kazuo Kashiyama

JSCE Journal of Applied Mechanics　12　195-203　2009/08
Publisher:
ISSN： 1345-9139
Finite cover method with multi-cover layers for the analysis of evolving discontinuities in heterogeneous media Peer-reviewed

Mao Kurumatani, Kenjiro Terada

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING　79　(1)　1-24　2009/07

DOI： 10.1002/nme.2545 　

ISSN： 0029-5981
エネルギー収支に基づくコンクリートの破壊靭性評価法に関する基礎的研究

車谷麻緒, 湯本達也, 寺田賢二郎, 秋山充良

コンクリート工学年次論文報告集　31　(2)　97-102　2009
Classification of Mechanical Failures of SOFC and Strategy for Evaluation of the Operational Margins Peer-reviewed

T. Kawada, S. Watanabe, S. Hashimoto, T. Sakamoto, A. Unemoto, M. Kurumatani, K. Sato, F. Iguchi, K. Yashiro, K. Amezawa, K. Terada, M. Kubo, H. Yugami, T. Hashida, J. Mizusaki

SOLID OXIDE FUEL CELLS 11 (SOFC-XI)　25　(2)　467-472　2009

DOI： 10.1149/1.3205556 　

ISSN： 1938-5862
MECHANISM OF SIZE EFFECT IN QUASI-BRITTLE MATERIALS BY FOCUSING ON THE MICRO-CRACK FORMATIONS Peer-reviewed

Mao Kurumatani, Kenjiro Terada

Doboku Gakkai Ronbunshuu A　65　(1)　216-227　2009/01

DOI： 10.2208/jsceja.65.216 　
MECHANISM OF SIZE EFFECT IN QUASI-BRITTLE MATERIALS BY FOCUSING ON THE MICRO-CRACK FORMATIONS Peer-reviewed

Mao Kurumatani, Kenjiro Terada, Takashi Kyoya, Tomonao Hashizume

Doboku Gakkai Ronbunshuu A　65　(1)　165-177　2009/01

DOI： 10.2208/jsceja.65.165 　
A method of viscoelastic two-scale analyses for FRP Peer-reviewed

Kenjiro Terada, Yasuaki Hamana, Norio Hirayama

Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A　75　(760)　1674-1683　2009
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.75.1674 　

ISSN： 0387-5008
Multi-scale thermo-elastic coupled analysis of porous media based on the homogenization method in consideration of the size of microstructures Peer-reviewed

Mao Kurumatani, Kenjiro Terada, Hiroshi Okumura

Transactions of the Japan Society for Computational Engineering and Science　2008　(29)　2008/12/01
Parameter Identification for Anisotropic Hyperelastic Materials by Numerical Material Testing Peer-reviewed

Kenjiro Terada, Takenori Inugai, Yasuaki Hamana, Akio Miyori, Norio Hirayama

Transactions of the Japan Society for Computational Engineering and Science　2008　(24)　2008/10/02
A Method of Numerical Material Testing in Nonlinear Multiscale Material Analyses Peer-reviewed

Kenjiro Terada, Takenori Inugai, Norio Hirayama

Transactions of the Japan Society of Mechanical Engineers. A　74　(744)　1084-1094　2008/08/25
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.74.1084 　

ISSN： 0387-5008

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A method of numerical material testing is developed for characterizing equivalent or macroscopic mechanical and/or other physical properties of composite materials with heterogeneous microstructures. The proposed method is prepared for testing on a variety of heterogeneous microstructures and nonlinear material behavior of constituents and their interfaces under various patterns of macroscopic loading. The numerical material testing in this method is intended to be carried out by means of the finite element method with a quasi-static implicit solution scheme in conjunction with the homogenization theory for periodic microstructures, i.e., unit cells.
A method for evaluating fracture energy of quasibrittle materials using cohesive crack model Peer-reviewed

Tatsuya Yumoto, Mao kurumatani, Masaki Yamada, Kenjiro Terada, Takashi Kyoya

JSCE Journal of Applied Mechanics　11　351-359　2008/08
Publisher:
DOI： 10.2208/journalam.11.351 　

ISSN： 1345-9139
Application of the explicit solution algorithm for cohesive crack model to three-dimensional crack propagation analysis of quasi-brittle materials Peer-reviewed

Mao Kurumatani, Kenjiro Terada, Takashi Kyoya

JSCE Journal of Applied Mechanics　11　211-220　2008/08

DOI： 10.2208/journalam.11.211 　
A method of dynamic fracture analysis for quasi-brittle materials by means of cohesive crack model Peer-reviewed

Mao Kurumatani, Satoshi Iwata, Kenjiro Terada, Shigenobu Okazawa, Kazuo Kashiyama

JSCE Journal of Applied Mechanics　11　211-220　2008/08
Publisher:
DOI： 10.2208/journalam.11.201 　

ISSN： 1345-9139
Grain Size Dependence of Tensile Strength of Polycrystalline Metals by Crystal-Plasticity-Damage Multi-Scale Analyses Peer-reviewed

WATANABE Ikumu, TERADA Kenjiro, AKIYAMA Masayoshi

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A　74　(739)　412-418　2008/03/25
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.74.412 　

ISSN： 0387-5008

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This work investigates the grain size dependence of the macroscopic tensile strength of polycrystalline metals by applying the two-scale finite element method, which is based on the homogenization theory combined with the elastic-plastic-damage constitutive model for single crystal grain. The degradation of the macroscopic stiffness is realized by the damage evolution in micro scale in our two-scale finite element analysis. It is demonstrated that the tensile strengths of polycrystalline metals exhibit the Hall-Petch type dependence on the grain size and that the less ductile the corresponding material behavior the smaller the grain size. Then this work also tries to clarify the microscopic mechanisms of these grain size dependences.
AN EXPLICIT SOLUTION ALGORITHM FOR COHESIVE CRACK MODEL AND ITS EVALUATION Invited Peer-reviewed

Mao Kurumatani, Kenjiro Terada

Doboku Gakkai Ronbunshuu A　64　(3)　627-638　2008/03

DOI： 10.2208/jsceja.64.627 　
Characterization of macroscopic tensile strength of polycrystalline metals with two-scale finite element analysis Peer-reviewed

Watanabe, Ikumu, Terada, Kenjiro, de Souza Neto, Eduardo Alberto, Peric, Djordje

JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS　56　(3)　1105-1125　2008/03

DOI： 10.1016/j.jmps.2007.06.001 　

ISSN： 0022-5096

eISSN： 1873-4782
MULTI-SCALE MULTI-PHYSICS ANALYSIS FOR DETERIORATION OF QUASI-BRITTLE MATERIALS INVOLVING MICRO-CRACK PROPAGATIONS Peer-reviewed

Mao Kurumatani, Kenjiro Terada

Doboku Gakkai Ronbunshuu A　64　(2)　363-375　2008/02

DOI： 10.2208/jsceja.64.363 　
A method for crack propagation analysis incorporated with nodal-integration FEM Peer-reviewed

Mao Kurumatani, Kenjiro Terada

Transactions of the Japan Society for Computational Engineering and Science　2008　(2)　2008/01/29
Veryfication study of micro-macro decoupling analysis on three dimentional plastic forming problem Peer-reviewed

WATANABE Ikumu, TERADA Kenjiro

Journal of applied mechanics　11　(11)　123-131　2008
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalam.11.123 　

ISSN： 1345-9139

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The approximate accuracy of the micro-macro decoupling analysis method is studied with a view to its application to predicting detailed micro-and macroscopic responses of polycrystalline metals subjected to plastic forming. A simple example problem assuming three dimensional cold-forming is set up for examining the micro-and macroscopic analysis results in comparison with the micro-macro simultaneous coupling analysis method. The qualitative reproducibility in both the micro-and macroscopic deformation states as well as the corresponding stress states is confirmed. And even the quantitative accuracy is obtained for the plastic-deformation-dominant forming process to some extent. It is also pointed that the accuracy in the responses especially during unloading process after the forming tends to depend on the employed macroscopic homogenized constitutive equation in the decoupling method.
DEVELOPMENT OF GLOBAL-LOCAL FINITE COVER METHOD AND ITS APPLICATION TO THE ANALYSIS OF CRACK GROWTH IN CONCRETE DUE TO REINFORCEMENT CORROSION Peer-reviewed

Mao Kurumatani, Kenjiro Terada

Doboku Gakkai Ronbunshuu A　64　(1)　15-26　2008/01

DOI： 10.2208/jsceja.64.16 　
Eulerian finite cover method for quasi-static equilibrium problems of hyperelastic bodies Peer-reviewed

K. Terada, A. Maruyama, M. Kurumatani

COMMUNICATIONS IN NUMERICAL METHODS IN ENGINEERING　23　(12)　1081-1094　2007/12

DOI： 10.1002/cnm.948 　

ISSN： 1069-8299
Finite cover method with multi-cover modeling Peer-reviewed

Mao Kurumatani, Kenjiro Terada

Transactions of the Japan Society for Computational Engineering and Science　2006　(29)　2007/10/17
Effects of frictional slip between crack interfaces to crack growth in quasi-brittle solids Peer-reviewed

Tateki Ishii, Takashi Kyoya, Kenjiro Terada

JSCE Journal of Applied Mechanics　10　343-350　2007/08

DOI： 10.2208/journalam.10.343 　
Image-based nodal-integration finite element method for non-linear analyses of composite materials Peer-reviewed

Mao Kurumatani, Kenjiro Terada

JSCE Journal of Applied Mechanics　10　91-100　2007/08

DOI： 10.2208/journalam.10.91 　
Computational aspects of tangent moduli tensors in rate-independent crystal elastoplasticity Peer-reviewed

K. Terada, I. Watanabe

COMPUTATIONAL MECHANICS　40　(3)　497-511　2007/08

DOI： 10.1007/s00466-006-0123-0 　

ISSN： 0178-7675
Performance assessment of nodal-integration finite element method Peer-reviewed

Mao Kurumatani, Takashi Kojima, Kenjiro Terada

Transactions of the Japan Society for Computational Engineering and Science　2007　(15)　2007/07/13
Numerical simulation for material processing by using the phase-field method and the homogenization method

Kazumi Matsui, Toshiyuki Koyama, Kenjiro Terada

Computational Plasticity - Fundamentals and Applications, COMPLAS IX　(2)　981-982　2007
Comparison of homogenization techniques in magnetostatic field problems Invited Peer-reviewed

J.S. Choi, J. Yoo, S. Nishiwaki, K. Terada

Transactions of the Korean Society of Mechanical Engineers, A　31　(3)　388-394　2007
Topology Optimization of Mechanical Structures Targeting Vibration Characteristics Invited Peer-reviewed

Nishiwaki, S, Maeda, Y, Izui, K, Yoshimura, M, Matsui, K, Terada, K

Journal of Environment and Engineering, Vol. 2 No. 3 (2007)　2　(3)　480-492　2007
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jee.2.480 　

ISSN： 1880-988X

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This paper proposes a structural topology optimization method for obtaining mechanical structures incorporating desired vibration characteristics for the design of mechanical resonators and vibromotors. First, a new type of homogenization design method is introduced, in which continuous material distributions are assumed using a continuous interpolation function at each node, in order to overcome numerical instabilities such as checkerboard patterns. Next, three design requirements for implementing specific vibration characteristics in the mechanical structures are clarified, namely eigen-frequency matching, eigen-mode control, and stiffness, and the corresponding objective functions are formulated. A new type of multi-objective function incorporating these three objective functions is proposed. The optimization problem is formulated using this multi-objective function, and an optimization algorithm is developed using Sequential Linear Programming (SLP). Finally, several examples are provided in order to confirm the usefulness of the generated optimal designs for vibrating mechanical structures.
The importance of finite element performance for characterizing the macroscopic material behavior with two-scale finite element analysis for polycrystalline metals Peer-reviewed

Neto Eduardo Alberto de Souza, PERIC Djordje, WATANABE Ikumu, TERADA Kenjiro

Journal of applied mechanics　10　(10)　167-174　2007
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalam.10.167 　

ISSN： 1345-9139

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We examine the finite element performance at micro scale for the evaluation of the macroscopic material behavior and strength with two-scale finite element analysis method incorporating the elastic-plasticdamage constitutive model for crystal grain. In the two-scale analysis, the intragranular deformations are non-homogeneous as a result of intergranular deformation even if the macroscopic deformation is simply homogeneous. Hence it is vital that the effect of finite element mesh discretizing each grain is examined in order to characterize the macroscopic material behavior. And then the two-scale analyses are conducted to assess the convergence of solutions with mesh refinement of each grain. Besides numerical simulations obtained with the F-bar element and the standard enhanced assumed strain element are compared against the standard displacement-based isoparametric element so as to assess the importance of finite element formulation on computational results.
ON ANALYSIS MODELS OF REINFORCED CORROSION AND THEIR CRACK BEHAVIOR OF CONCRETE Peer-reviewed

Mao Kurumatani, Kenjiro Terada, Makoto Hisada

Doboku Gakkai Ronbunshuu A　63　(1)　167-178　2007/01

DOI： 10.2208/jsceja.63.167 　
Finite cover method for progressive failure with cohesive zone fracture in heterogeneous solids and structures Peer-reviewed

K. Terada, T. Ishii, T. Kyoya, Y. Kishino

COMPUTATIONAL MECHANICS　39　(2)　191-210　2007/01

DOI： 10.1007/s00466-005-0017-6 　

ISSN： 0178-7675
Development of numerical simulator by coupled electro-mechanical analysis of ultrasonic piezoelectric transducer Peer-reviewed

Masaki Yamada, Hiroyuki Miyakoshi, Kenjiro Terada

JSCE Journal of Applied Mechanics　9　1121-1129　2006/08

DOI： 10.2208/journalam.9.1121 　
Multiscale analysis method for quasi-brittle heterogeneous materials involving micro-crack propagations Peer-reviewed

Tateki Ishii, Takashi Kyoya, Naoi Nishizawa, Kenjiro Terada

JSCE Journal of Applied Mechanics　9　273-282　2006/08

DOI： 10.2208/journalam.9.273 　
Analysis of crack-paths in concrete due to reinforcement corrosion and their underlying mechanism Peer-reviewed

Mao Kurumatani, Masahiro Ishihata, Tateki Ishii, Kenjiro Terada

JSCE Journal of Applied Mechanics　9　185-194　2006/08

DOI： 10.2208/journalam.9.185 　
Failure analysis of quasi-brittle materials involving multiple mechanisms on fractured surfaces Peer-reviewed

Tateki Ishii, Kenjiro Terada, Takashi Kyoya

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING　67　(7)　960-988　2006/08

DOI： 10.1002/nme.1656 　

ISSN： 0029-5981
Structural topology optimization of vibrating structures with specified eigenfrequencies and eigenmode shapes Peer-reviewed

Y. Maeda, S. Nishiwaki, K. Izui, M. Yoshimura, K. Matsui, K. Terada

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING　67　(5)　597-628　2006/07

DOI： 10.1002/nme.1626 　

ISSN： 0029-5981
Examination of finite cover approximations for imposing interface compatibility conditions in generalized elements - A sort of patch tests - Peer-reviewed

Mao Kurumatani, Kenjiro Terada

Transactions of the Japan Society for Computational Engineering and Science　2006　(14)　2006/04/21
A MULTI-SCALE HEAT CONDUCTION ANALYSIS METHOD FOR POROUS MEDIA IN CONSIDERATION OF MICROSCOPIC HEAT TRANSFER Peer-reviewed

Mao Kurumatani, Kenjiro Terada

Doboku Gakkai Ronbunshuu A　62　(4)　772-781　2006/04

DOI： 10.2208/jsceja.62.822 　
A MULTI-SCALE MULTI-PHYSICS ANALYSIS METHOD FOR MASS CONCENTRATION AND DEFORMATION PROBLEMS Peer-reviewed

Mao Kurumatani, Kenjiro Terada

Doboku Gakkai Ronbunshuu A　62　(2)　425-439　2006/02

DOI： 10.2208/jsceja.62.425 　
FAILURE ANALYSIS INVOLVING FRICTIONAL CONTACT ON CRACK INTERFACES Peer-reviewed

Tataki Ishii, Takashi Kyoya, Kenjiro Terada, Yuji Kishino

Doboku Gakkai Ronbunshuu A　62　(2)　371-383　2006/02

DOI： 10.2208/jsceja.62.371 　
ON FINITE ELEMENT MESH CONNECTION METHODS FOR DOMAIN DECOMPOSITION PROBLEMS Peer-reviewed

Mao Kurumatani, Kenjiro Terada

土木学会論文集A　62　(2)　345-361　2006/02

DOI： 10.2208/jsceja.62.345 　
Topology optimization with CAMD for structures undergoing finite deformation

K. Matsui, K. Terada, S. Nishiwaki

Solid Mechanics and its Applications　137　333-342　2006
Publisher: Springer Verlag
DOI： 10.1007/1-4020-4752-5_33 　

ISSN： 1875-3507
Structural topology optimization of mechanical resonators, actuators and sensors

Shinji Nishiwaki, Emilio C.N. Silva, Kazumi Matsui, Kenjiro Terada, Kazuhiro Izui, Masataka Yoshimura

Solid Mechanics and its Applications　137　291-299　2006
Publisher: Springer Verlag
DOI： 10.1007/1-4020-4752-5_29 　

ISSN： 1875-3507
Topology optimization method for nonlinear solids Peer-reviewed

K. Matsui, K. Terada, S. Nishiwaki

COMPUTATIONAL METHODS, PTS 1 AND 2　923-+　2006
Comparative Studies of Topology Optimization Using Continuous Approximation of Material Distribution Invited Peer-reviewed

Lim, Y. -S, Yoo, J. -H, Terada, K, Nishiwaki, S, Min, S.-J

Transactions of KSME (A), Vol.30, No.2 (2006)　164-170　2006
Topology optimization with CAMD for structures undergoing finite deformation Peer-reviewed

K. Matsui, K. Terada, S. Nishiwaki

IUTAM SYMPOSIUM ON TOPOLOGICAL DESIGN OPTIMIZATION OF STRUCTURES, MACHINES AND MATERIALS: STATUS AND PERSPECTIVES　137　333-+　2006

ISSN： 0925-0042
Structural topology optimization of mechanical resonators, actuators and sensors Peer-reviewed

Shinji Nishiwaki, Emilio C. N. Silva, Kazumi Matsui, Kenjiro Terada, Kazuhiro Izui, Masataka Yoshimura

IUTAM SYMPOSIUM ON TOPOLOGICAL DESIGN OPTIMIZATION OF STRUCTURES, MACHINES AND MATERIALS: STATUS AND PERSPECTIVES　137　291-+　2006

ISSN： 0925-0042
Effects of shape and size of crystal grains on the strengths of polycrystalline metals Peer-reviewed

Terada, Kenjiro, Watanabe, Ikumu, Akiyama, Masayoshi

INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING　4　(4)　445-460　2006

DOI： 10.1615/IntJMultCompEng.v4.i4.30 　

ISSN： 1543-1649

eISSN： 1940-4352
Multiscale modeling for planar lattice microstructures with structural elements Peer-reviewed

Isao Saiki, Ken Ooue, Kenjiro Terada, Akinori Nakajima

International Journal for Multiscale Computational Engineering　4　(4)　429-444　2006

DOI： 10.1615/IntJMultCompEng.v4.i4.20 　

ISSN： 1543-1649
MULTI-SCALE ANALYSIS FOR POLYCRYSTALLINE METALS WITH CONTINUUM DAMAGE MODEL Peer-reviewed

WATANABE Ikumu, TERADA Kenjiro

Doboku Gakkai Ronbunshuu A　62　(4)　772-781　2006
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jsceja.62.772 　

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A rate-independent damage-elastic-plastic constitutive model for single crystals is proposed and incorporated with the method of two-scale analysis method to characterize both the deformation characteristics and the strength of polycrystalline metals. First, we introduce a relevant kinematics associated with the multiplicative decomposition of the deformation gradient into elastic, plastic and damage deformation components. Next, the evolution equations of state variables are formulated with the principle of maximum dissipation in the framework of multisurface plasticity, and the associated state update algorithm is developed along with the corresponding consistent tangent moduli. After examining the basic characteristics of the proposed constitutive model, we demonstrate the promise and potential of the developed two-scale analysis method.
Finite cover method for physically and geometrically nonlinear problems

Kenjiro Terada, Mitsuteru Asai

Lecture Notes in Computational Science and Engineering　43　169-190　2005/12/01

ISSN： 1439-7358
Analysis of microscopic yielding behaviour of carbon steel under macroscopic loading Invited Peer-reviewed

M Akiyama, K Matsui, K Terada

TETSU TO HAGANE-JOURNAL OF THE IRON AND STEEL INSTITUTE OF JAPAN　91　(11)　803-808　2005/11

DOI： 10.2355/tetsutohagane1955.91.11_803 　

ISSN： 0021-1575

eISSN： 1883-2954
An application of discontinuous Galerkin finite cover method to discontinuous deformation analysis Peer-reviewed

Tateki ISHII, Kenjiro TERADA, Takashi KYOYA, Yuji KISHINO, Mao KURUMATANI

JSCE Journal of Applied Mechanics　8　327-334　2005/08/22

DOI： 10.2208/journalam.8.327 　
Development of discontinuous Galerkin finite cover method and its evaluation Peer-reviewed

Mao KUTUMATANI, Kenjiro TERADA

JSCE Journal of Applied Mechanics　8　215-224　2005/08/22

DOI： 10.2208/journalam.8.215 　
An integrated procedure for three-dimensional structural analysis with the finite cover method Peer-reviewed

K Terada, M Kurumatani

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING　63　(15)　2102-2123　2005/08

DOI： 10.1002/nme.1356 　

ISSN： 0029-5981
Approximation properties of generalized elements in higher-order finite cover approximation Peer-reviewed

Mao KURUMATANI, Kenjiro TERADA

Transaction of JSCE　794　(I-72)　131-142　2005/07/01
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2005.794_131 　

ISSN： 0289-7806

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The finite cover method (FCM) is known as the generalization of finite element method (FEM) and enjoys peculiar elements that partially have physical domains. We name them the generalized elements in this study and examine their performance by using higher-order finite cover approximation within the framework of the FEM. First, elemental deformability is studied in comparison with Wilson-Taylor's element (QM6), 8 node quadrilateral element (Q8) and lowest-order generalized element. Secondly, the sensitivity of the performance of the generalized elements to their distortion is compared with that of finite elements. Finally, after making the convergence study for the Cook's membrane problem and compiling all the results in this study, we conclude that the performance of higher-order generalized elements in the FCM are equivalent or slightly superior to that of finite elements. It is to be noted that the studies also apply to the X-FEM and the GFEM.
Development of fracture simulation by the finite cover method using interface element Peer-reviewed

Tateki ISHII, Kenjiro TERADA, Takashi ISHII, Yuji KISHINO

Transaction of JSCE　794　(I-72)　213-225　2005/07/01
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2005.794_213 　

ISSN： 0289-7806

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A computational method for the consistent simulation of fracture phenomena, such as exfoliation of material interfaces and cracking inside materials, is presented. The exfoliation of material interfaces is simulated in terms of the interface element which combined the Lagrange multipliers and the cohesive crack model, the cracking inside materials is rationally carried out by combining the criteria based on tensile strength and the cohesive crack model. The Finite cover method (FCM) can trace the path of discontinuities completely independent of the mesh structure, and connect these techniques smoothly. Representative numerical examples demonstrate well the performance of the proposed method.
Finite cover method with mortar elements for elastoplasticity problems Peer-reviewed

M Kurumatani, K Terada

COMPUTATIONAL MECHANICS　36　(1)　45-61　2005/06

DOI： 10.1007/s00466-004-0641-6 　

ISSN： 0178-7675
An Optimum Design Method for Vibrating Mechanical Structures Based on Topology Optimization Techniques Invited Peer-reviewed

Maeda, Y, Nishiwaki, S, Izui, K, Yoshimura, M, Matsui, K, Terada, K

6th World Congress on Structural and Multidisciplinary Optimization, Rio de Janeiro, Brazil, No. 3911.　2005/05
A study on stress update algorithm and linearization scheme for single crystal plasticity Peer-reviewed

Ikumu WATANABE, Kenjiro TERADA

Transaction of JSCES　8　2005/04/28

ISSN： 1344-9443
コンクリートのマルチスケール・モデリング

中村光, 斉藤成彦, 石田哲也, 栗原哲彦, 佐伯竜彦, 寺田賢二郎, 永井学志, 中村成春, 細川佳史, 森泉和人, 嶋毅, 宮野和樹, 長井宏平

コンクリート工学 = Concrete journal　43　(3)　64-69　2005/03/01
Publisher: 公益社団法人日本コンクリート工学会
DOI： 10.3151/coj1975.43.3_64 　

ISSN： 0387-1061
Direct observation of microscopic plastic deformation of stainless steel using lattice drawn by focused ion beam of Ga+ Invited Peer-reviewed

M Akiyama, Y Neishi, A Taniyama, K Terada

MATERIALS SCIENCE AND TECHNOLOGY　21　(3)　274-280　2005/03

DOI： 10.1179/174328405X27089 　

ISSN： 0267-0836
Topology optimization of mechanical structures targeting vibration characteristics Peer-reviewed

Yasunori MAEDA, Shinji NISHIWAKI, Kazuhiro IZUI, Masataka YOSHIMURA, Kazumi MATSUI, Kenjiro TERADA

Transaction of JSME, Series C　71　(703)　813-820　2005/03/01
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaic.71.813 　

ISSN： 0387-5024

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This paper proposes a structural topology optimization method for obtaining mechanical structures incorporating desired vibration characteristics for the design of mechanical resonators and vibromotors. First, a new type of homogenization design method is introduced, in which the continuous material distributions are assumed using a continuous interpolation function at each node, in order to overcome numerical instabilities such as checkerboard patterns. Next, three design requirements to implement specific vibration characteristics in the mechanical structures are clarified, namely eigen-frequency matching, eigen-mode control, and stiffness, and the corresponding objective functions are formulated. A new type of multi-objective function incorporating the three objective functions is proposed. The optimization problem is formulated using this multi-objective function, and an optimization algorithm is developed using Sequential Linear Programming (SLP). Finally, several examples are provided in order to confirm the usefulness of the generated optimal designs for vibrating mechanical structures.
Two-scale analysis for deformation-induced anisotropy of polycrystalline metals Peer-reviewed

Watanabe, I, K Terada, M Akiyama

COMPUTATIONAL MATERIALS SCIENCE　32　(2)　240-250　2005/02

DOI： 10.1016/j.commatsci.2004.08.002 　

ISSN： 0927-0256
Development of material design simulator by using the pahse-field method and the homogenization method

Kazumi Matsui, Toshiyuki Koyama, Kenjiro Terada

Computational Plasticity: Fundamentals and Applications - Proceedings of the 8th International Conference on Computational Plasticity, COMPLAS VIII　(1)　581-582　2005
On integrated earthquake simulator prototype: Combination of numerical simulation and geographical information system Peer-reviewed

Tsuyoshi Ichimura, Muneo Hori, Kenjiro Terada, Takahiro Yamakawa

Structural Engineering/Earthquake Engineering　22　(2)　2005

DOI： 10.2208/jsceseee.22.233s 　

ISSN： 0289-8063

eISSN： 0289-8063
Study on multi-scale modeling of plasticity by atomic model Peer-reviewed

Isao Saiki, Shigeri Kanke, Akinori Nakajima, Kenjiro Terada

Structural Engineering/Earthquake Engineering　22　(2)　209s-217s　2005

DOI： 10.2208/jsceseee.22.209s 　

ISSN： 0289-8063
Decoupled micro-macro analysis method for two-scale BVPs in nonlinear homogenization theory Peer-reviewed

Ikumu WATANABE, Kenjiro TERADA

JSCE Journal of Applied Mechanics　8　277-285　2005
Publisher:
DOI： 10.2208/journalam.8.277 　

ISSN： 1345-9139
Evaluation of Induced Anisotropy in Polycrystalline Metals Based on Homogenization Method Peer-reviewed

WATANABE Ikumu, TERADA Kenjiro, MATSUI Kazumi, AKIYAMA Masayoshi, NEISHI Yutaka

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A　70　(699)　1558-1565　2004/11/25
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.70.1558 　

ISSN： 0387-5008

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Macro-scale anisotropic mechanical behavior of polycrystalline meals is characterized by incorporating the micro-scale constitutive model of single crystal plasticity into the two-scale modeling based on the mathematical homogenization theory. The two-scale simulations are conducted to characterize the macro-scale anisotropy induced by micro-scale plastic deformation of the polycrystalline aggreagate. In the simulations, the micro-scale representative volume element of a polycrystalline aggregate is uniformly loaded in one direction, unloaded to macroscopially zero stress in a certain stage of deformation and then re-loaded in the different directions. Then the effect of the intergranular and intragranular behaviors are examined by several ways of illustrations of plastic deformation process. In particular, we are concerned with the concentrations of accumulated plastic strain and effective stress in the neighborhood of grain boundaries. In addition, the principal slip directions in each loading state are shown to examine the effect of self and latent hardenig on the deformation-induced anisotropy.
Performance assessment of generalized elements in the finite cover method Peer-reviewed

K Terada, M Kurumatani

FINITE ELEMENTS IN ANALYSIS AND DESIGN　41　(2)　111-132　2004/11

DOI： 10.1016/j.finel.2004.05.001 　

ISSN： 0168-874X
Design of Mechanical Resonators Based on Topology Optimization Technique Invited Peer-reviewed

Maeda, Y, Nishiwaki, S, Izui, K, Yoshimura, M, Matsui, K, Terada, K

Proceedings of the Third China-Japan-Korea Joint Symposium on Optimization of Structural and Mechanical Systems Kanazawa, Japan　753-758　2004/10
Numerical re-examination of the micro-scale mechanism of the Bauschinger effect in carbon steels Peer-reviewed

K Terada, K Matsui, M Akiyama, T Kuboki

COMPUTATIONAL MATERIALS SCIENCE　31　(1-2)　67-83　2004/09

DOI： 10.1016/j.commatsci.2004.01.037 　

ISSN： 0927-0256
Structural topolgy optimiation of compliant mechanism (In cases where the ratio of the displacement at the input location to the displacement at the output location is included in an objective function) Peer-reviewed

Ryo Hosoyama, Shinji Nishiwaki, Kazuhiro Izui, Yoshitaka Yoshimura, Kazumi Matsui, Kenjiro Terada

Transaction of JSME, Series A　70　(696)　2384-2391　2004/08

DOI： 10.1299/kikaic.70.2384 　
Three-dimensional finite cover method with interface elements Peer-reviewed

Mao Kurumatani, Kenjiro Terada

Journal of Applied Mechancis　7　441-450　2004/08

DOI： 10.2208/journalam.7.441 　
A NON-LOCAL VOXEL FINITE ELEMENT METHOD AND ITS APPLICATION TO FAILURE ANALYSES Peer-reviewed

ASAI Mitsuteru, YAMAGISHI Michihiro, TERADA Kenjiro, NAGAI Gakuji

Doboku Gakkai Ronbunshu　759　(759)　233-245　2004/04/21
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2004.759_233 　

ISSN： 0289-7806

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A non-local voxel FEM is developed for simulating the failure phenomena of heterogeneous brittle materials. The micro-scale or meso-scale morphology of heterogeneous materials is realized by the image-based modeling technique, whereas the cracking is simulated by the element vanish technique. Also, the nonlocal technique of integral-averaging type is effectively utilized to avoid both the stress oscillation errors on the material interfaces and the spurious dependency on the voxel size for crack propagation problems. The three-dimensional numerical simulations successfully demonstrate the cracking phenomena induced by the micro-scale heterogeneities and the so-called biaxial effect that is typical in the strength characteristics of concrete.
Nonlinear multi-scale modeling with frame elements for cellular materials Peer-reviewed

Ken Ooue, Isao Saiki, Kenjiro Terada, Akinori Nakajima

Structural Engineering/Earthquake Engineering　21　(1)　67-75　2004/04

DOI： 10.2208/jsceseee.21.67s 　

ISSN： 0289-8063
Continuous approximation of material distribution for topology optimization Peer-reviewed

K Matsui, K Terada

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING　59　(14)　1925-1944　2004/04

DOI： 10.1002/nme.945 　

ISSN： 0029-5981
Two-scale finite element analysis of heterogeneous solids with periodic microstructures Peer-reviewed

K Matsui, K Terada, K Yuge

COMPUTERS & STRUCTURES　82　(7-8)　593-606　2004/03

DOI： 10.1016/j.compstruc.2004.01.004 　

ISSN： 0045-7949
ON STANDARDIZATION OF VARIOUS EARTHQUAKE RESISTANCE DESGIN CODES FOR IMPROVING GOVERNMENT ENGINEERING ABILITY

HORI Muneo, ICHIMURA Tsuyoshi, TERADA Kenjiro

SOCIOTECHNICA　2　444-454　2004
Publisher: Sociotechnology Research Network
DOI： 10.3392/sociotechnica.2.444 　

ISSN： 1349-0184

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It will be an important task for local government officers to improve their engineering ability of foreseeing possible earthquake damages. To this end, this paper studies the standardization of earthquake resistance design codes of various structures. Taking advantage of informatics methodology, we reconstruct flowcharts of various design codes such that the earthquake resistance design can be described in a common framework. The usage of object to express each design procedure is effective in standardization. The resulting standard codes which are expressed in terms of common description are expected to help government officers understand the concepts and methods of various earthquake resistance design codes to some proper extent that is needed for them.
Evaluation of grain effects by multi-scale modeling based on homogenization method Peer-reviewed

Ikumu Watanabe, Atsushi Maruyama, Kenjiro Terada, Masayoshi Akiyama

Journal of Applied Mechanics　7　(1)　365-371　2004
Publisher:
DOI： 10.2208/journalam.7.365 　

ISSN： 1345-9139
Finite cover method for linear and non-linear analyses of heterogeneous solids Peer-reviewed

K Terada, M Asal, M Yamagishi

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING　58　(9)　1321-1346　2003/11

DOI： 10.1002/nme.820 　

ISSN： 0029-5981
Hierarchical finite elements for average behavior of composite structures Peer-reviewed

Kai OIDE, Tsuyoshi ICHIMURA, Yoshiteru ISHIBASHI, Kenjiro TERADA

土木学会論文集　745　(I-65)　15-24　2003/10
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2003.745_15 　

ISSN： 0289-7806

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Hierarchical finite elements are examined for average mechanical behavior of composite structures. The formulation is formally similar to that of the overlaying mesh method, but its main purpose is to derive the element stiffness that is equivalent to the actual composite structures with local heterogeneities. The resulting elements possess additional internal degrees of freedom in the local finite element mesh for improving the performance and thus are nonconforming. In other words, the local structure with actual heterogeneities is reflected on the evaluation of the element stiffness matrix of a global element, so that a global element behavior is enhanced by the local degrees of freedom. Several numerical analyses are performed to examine the validity and accuracy of the proposed hierarchical finite elements.
Global-local analysis of granular media in quasi-static equilibrium Peer-reviewed

K Kaneko, K Terada, T Kyoya, Y Kishino

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES　40　(15)　4043-4069　2003/07

DOI： 10.1016/S0020-7683(03)00209-9 　

ISSN： 0020-7683
Meso-scopic numerical analysis of concrete structures by a modified lattice model

Mitsuteru Asai, Kenjiro Terada, Kiyohiro Ikeda, Hiroyuki Suyama, Katashi Fujii

Structural Engineering/Earthquake Engineering　20　(731)　19-30　2003/04/01
Publisher: 土木学会
DOI： 10.2208/jsceseee.20.43s 　

ISSN： 0289-8063
ON GENERATION AND CONVEY OF EARTHQUAKE INFORMATION FOR PROMOTING EARTHQUAKE DISASTER PREVENTION

HORI Muneo, ICHIMURA Tsuyoshi, TERADA Kenjiro

SOCIOTECHNICA　1　367-373　2003
Publisher: Sociotechnology Research Network
DOI： 10.3392/sociotechnica.1.367 　

ISSN： 1349-0184

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Consciousness of earthquake hazard is important for promoting earthquake disaster prevention. However, it is not at high level, partially due to subjective recognition of hazards. Weather forecast has attained high reliability, making recognition of weather disaster more objective. We study development of weather forecast technologies and contribution to make weather information more trust-worthy. Comparing these technologies with the ones for earthquake information, we discuss the direction of generating and delivering earthquake information to achieve more objective recognition of hazards. It is concluded that the key issues are to deliver the processes of generating earthquake information even if they contain mistakes, as well as to increase the quality of the information.
Bifurcation analysis on soil specimens exhibiting diffuse deformation modes and localized slip planes

Y Yamakawa, K Ikeda, K Terada, K Torii

DEFORMATION CHARACTERISTICS OF GEOMATERIALS　1　1035-1042　2003
Symmetry breaking bifurcation in various soils under shear

K Ikeda, K Terada, Y Yamakawa

DEFORMATION CHARACTERISTICS OF GEOMATERIALS　1　921-929　2003
セル構造材料のための骨組要素を用いた非線形マルチスケール解析 Peer-reviewed

大植健, 斉木功, 寺田賢二郎, 中島章典

土木学会論文集I　724　(I-62)　249-256　2003/01
Publisher:
DOI： 10.2208/jscej.2003.724_249 　

ISSN： 0289-7806
せん断帯分岐モードと強不連続変形の有限変形解析 Peer-reviewed

Yuki Yamakawa, Kiyohiro Ikeda, Kenjiro Terada, Keisuke Sato, Kunio Torii

土木学会論文集III　743　(III-64)　59-76　2003
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2003.743_59 　

ISSN： 0289-7806

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The shear band bifurcation mode and the progress of the discontinuous displacement field are numerically analyzed with a finite-element method. Kinematics and criteria of shear band bifurcation mode in multiplicative hyperelasto-plastic materials are presented, and a finite-element method for finite deformation with enhanced incompatible mode, which can kinematically express the discontinuous field, is adopted. Examination of the localization criteria reveals that the shear band mode can be detected even in the associative strain-hardening materials. Several numerical results show the significance and the effectiveness of the consideration to the shear band kinematics in the numerical analysis for strain localization problems.
Trigger for the occurrence of grain coarsening phenomenon of BS304S31 austenite stainless steel under small plastic strain at high temperature Peer-reviewed

M Akiyama, Y Neishi, Y Adachi, K Terada

ENGINEERING COMPUTATIONS　20　(5-6)　499-512　2003

DOI： 10.1108/02644400310488736 　

ISSN： 0264-4401
連続的材料分布の節点補間によるトポロジー最適化手法 Peer-reviewed

松井和己, 寺田賢二郎

日本機械学会論文集　69　(684)　1257-1264　2003
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.69.1257 　

ISSN： 0387-5008

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We propose a new method for topology optimization, which is free from numerical instabilities such as checkerboard patterns and mesh-dependency, without introducing any additional constraint parameters. This aim is accomplished by the introduction of finite element approximation for continuous material distribution in a fixed design domain. That is, the continuous distribution of microstructures, or equivalently design variables, is realized in the whole design domain in the context of the homogenization design method (HDM), by the discretization with finite element interpolations. By virtue of this continuous FE approximation of design variables, discontinuous distribution like checkerboard patterns disappears without any filtering schemes. We call this technique the method of continuous approximation of material distribution (CAMD) to emphasize the continuity imposed on the "material field". Two representative numerical examples are presented to demonstrate the capability and the efficiency of the proposed approach against the numerical instabilities.
統合地震シミュレータにおける高分解能強震動シミュレータと都市域の電子情報の利用について―地盤構造の推定方法が強震動分布に及ぼす影響の基礎検討とGISを中心とした統合地震シミュレータの雛形の構築― Peer-reviewed

市村強, 堀宗朗, 寺田賢二郎, 山川貴弘

土木学会　6　615-622　2003
Publisher:
DOI： 10.2208/journalam.6.615 　

ISSN： 1345-9139
有限被覆法の弾塑性問題への適用とその性能評価 Peer-reviewed

車谷麻緒, 浅井光輝, 寺田賢二郎

JSCE Jouranal of Applied Mechanics　6　247-256　2003
Publisher:
DOI： 10.2208/journalam.6.247 　

ISSN： 1345-9139
Multi-scale analysis for polycrystalline metals Peer-reviewed

WATANABE I.

Journal of Applied Mechanics,JSCE　6　239-246　2003
Publisher:
DOI： 10.2208/journalam.6.239 　

ISSN： 1345-9139
有限被覆法による不連続変形解析 Peer-reviewed

浅井光輝, 寺田賢二郎

JSCE Jouranal of Applied Mechanics　6　193-200　2003

DOI： 10.2208/journalam.6.193 　
要素寸法と材料種類の異なる不整合メッシュに対するdual-Schur mortar法の適用性について Peer-reviewed

生出佳, 寺田賢二郎, 市村強

JSCE Jouranal of Applied Mechanics　6　175-184　2003
Publisher:
DOI： 10.2208/journalam.6.175 　

ISSN： 1345-9139
ボクセルモデルと界面要素を用いた局所的非均質構造に対するグローバル・ローカル解析 Peer-reviewed

石井建樹, 寺田賢二郎, 京谷孝史, 岸野佑次

JSCE Jouranal of Applied Mechanics　6　141-150　2003
Publisher:
DOI： 10.2208/journalam.6.141 　

ISSN： 1345-9139
原子モデルによる塑性のマルチスケールモデリングに関する一考察 Peer-reviewed

斉木功, 菅家茂理, 中島章典, 寺田賢二郎

JSCE Jouranal of Applied Mechanics　6　123-130　2003
Publisher:
DOI： 10.2208/journalam.6.123 　

ISSN： 1345-9139
解析的平均手法を用いた複合材料の平面ひずみ有限要素 Peer-reviewed

樋口耕平, 岩熊哲夫, 京谷孝史, 寺田賢二郎

JSCE Jouranal of Applied Mechanics　6　107-116　2003
Publisher:
DOI： 10.2208/journalam.6.107 　

ISSN： 1345-9139
Two-scale kinematics and linearization for simultaneous two-scale analysis of periodic heterogeneous solids at finite strain Peer-reviewed

K Terada, Saiki, I, K Matsui, Y Yamakawa

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING　192　(31-32)　3531-3563　2003

DOI： 10.1016/S0045-7825(03)00365-7 　

ISSN： 0045-7825
非線形均質化理論に基づく骨組要素を用いたセル構造材料のマルチスケール解析 Peer-reviewed

斉木功, 大植健, 寺田賢二郎, 中島章典

日本機械学会論文集　69　(680)　786-793　2003
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.69.786 　

ISSN： 0387-5008

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Cellular materials consist of lattice-like microstructures are usually treated as continua which have equivalent macroscopic mechanical properties for structural analysis. Whereas the linear theory that estimates the equivalent properties for composites include cellular materials is mature, the theory and the methodology for the nonlinear analysis of cellular materials remain active fields of research. Then, in this context, we apply the homogenization method, which utilizes multiple scales and realizes macro and micro coupling multi-scale analysis, to cellular materials. Frame elements are employed in the multi-scale analysis based on the homogenization method since it is rational from computational viewpoint for discretizing the lattice-like microstructure. Finally, we show some numerical examples of the nonlinear multi-scale analysis of cellular materials in order to validate our multi-scale analysis.
Meso-scopic numerical analysis of concrete structures by a modified lattice model Peer-reviewed

M. Asai, K. Terada, K. Ikeda, H. Suyama, K. Fujii

Journal of Structural Mechanics and Earthquake Engineering　731　(I-63)　19-30　2003
Publisher:
DOI： 10.2208/jscej.2003.731_19 　

ISSN： 0289-7806
Consistent Topology Optimization Method for Hyperelastic Materials Invited Peer-reviewed

Matsui, K, Terada K, Nishiwaki S

The Second China-Japan-Korea Joint Symposium on Optimization of Structural and Mechanical Systems (CJK-OSM 2), Busan, Korea　171-176　2002/11
Influence of carbon content and carbide morphology of carbon steels on stress-strain curve in vicinity of yield point Peer-reviewed

M Akiyama, T Kuboki, K Oikawa, K Matsui, K Terada

MATERIALS SCIENCE AND TECHNOLOGY　18　(11)　1272-1278　2002/11

DOI： 10.1179/026708302225006151 　

ISSN： 0267-0836
Imperfection sensitive variation of critical loads at hilltop bifurcation point Peer-reviewed

K Ikeda, K Oide, K Terada

INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE　40　(7)　743-772　2002/04

DOI： 10.1016/S0020-7225(01)00098-2 　

ISSN： 0020-7225
Fundamental solutions for a fluid-saturated, transversely isotropic, poroelastic solid Peer-reviewed

Kenjiro Terada, Takashi Kyoya, Motoki Kazama, Kiho Lee, Lizhu Oyang

International Journal for Numerical and Analytical Methods in Geomechanics　26　(3)　299-321　2002/03

DOI： 10.1002/nag.202 　

ISSN： 0363-9061
Imperfection sensitivity and probabilistic variation of tensile strength of steel members Peer-reviewed

S Okazawa, K Oide, K Ikeda, K Terada

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES　39　(6)　1651-1671　2002/03

DOI： 10.1016/S0020-7683(01)00258-X 　

ISSN： 0020-7683
Image-based modelling and analysis of microstructures for two-scale problems in geomechanics Peer-reviewed

K Terada, T Kyoya, M Kazama, K Lee, L Oyang

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS　26　(3)　273-297　2002/03

DOI： 10.1002/nag.201 　

ISSN： 0363-9061
構造要素を用いたミクロモデルによるマルチスケールモデリングとそのセル構造体への適用 Peer-reviewed

斉木功, 大植健, 中島章典, 寺田賢二郎

No.20020004　2002/02/04
Nonlinear Multi-Scale Analysis of Cellular Solids with Microstructural Bifurcation

SAIKI Isao, OOUE Ken, TERADA Kenjiro, NAKAJIMA Akinori

Proceedings of the 1992 Annual Meeting of JSME/MMD　2002　61-62　2002
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmezairiki.2002.0_61 　
Finite Element Analysis for Strongly Discontinuous Shear Band Mode Induced by Material Instability at Finite Strain

YAMAKAWA Yuki, TERADA Kenjiro, IKEDA Kiyohiro, SATOH Keisuke, TORII Kunio

Proceedings of the 1992 Annual Meeting of JSME/MMD　2002　123-124　2002
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmezairiki.2002.0_123 　
Influences of Microstructural Morphology in Carbon Steels on the Initial Yielding Behaviour and the Bauschinger's Effect

AKIYAMA Masayoshi, KUBOKI Takashi, NEISHI Yutaka, MATSUI Kazumi, TERADA Kenjiro

Proceedings of the 1992 Annual Meeting of JSME/MMD　2002　127-128　2002
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmezairiki.2002.0_127 　

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Calculated results by the homogenization methods were compared with the observed results by TEM to validate that morphology of carbide in the microstructure affects the mechanical properties of high carbon steel in the vicinity of initial yield point. The material was 0.80Cmass% carbon steel, and behaviours of two steels prepared by different thermal treatment were compared; (1) perfectly pearlitic structure, and (2) spheroidized carbide structure. It was also shown that similar mechanism occurring in the microstructure in the vicinity of initial yield point also applies to the mechanism dominating the Bauschinger's effect of these two steels.
On the influence of morphology of carbide in a carbon-steel on the appearance of initial yielding

MATSUI Kazumi, TERADA Kenjiro, AKIYAMA Masayoshi, NEISHI Yutaka

Proceedings of the 1992 Annual Meeting of JSME/MMD　2002　59-60　2002
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmezairiki.2002.0_59 　
Two-Scale analysis of Mechanical Behavior of fissured rock mass

T. Kyoya, H. Nishioka, K. Terada

5th World Congress on Computaional Mechanics, Abstracts　2　367　2002
Quasi-static two-scale analysis of granular materials

K. Kaneko, T. Kyoya, Y. Kishino, K. Terada

5th World Congress on Computaional Mechanics, Abstracts　2　366　2002
構造部材強度の分岐理論に基づく確率評価法 Peer-reviewed

生出佳, 池田清宏, 寺田賢二郎, 藤井堅, 岡澤重信

土木学会論文集I　696　(I-58)　85-98　2002/01/01
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2002.696_85 　

ISSN： 0289-7806

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A method of stochastic evaluation of the strength of structural members is developed by the bifurcation theory. Knowing that the strength of slender specimens/members is governed by the so-called hilltop bifurcation point, which implies the coincidental double critcal point of limit and bifurcation points, we derive a system of bifurcation equations for the local behavior at this special double critical point. On the basis of this system of equations, we formulate an imperfection sensitivity law and, in turn, the probability density function of critical loads, assuming that initial imperfections are subject to a multi-variate normal distribution. In addition, the associated formulas for a limit point are presented for comparison. The validity of the theoretical developments is assessed through its application to a simple truss structure, whereas the feasibility and capability of the proposed method is demonstrated for the data sets obtained in actual experiments and numerical simulations of structural members.
マルチスケールモデリングによるBauschinger効果の発現メカニズムの解明 Peer-reviewed

TERADA Kenjiro

日本機械学会論文集　68　(675)　1559-1566　2002
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.68.1559 　

ISSN： 0387-5008

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The Bauschinger effect of metals is explored by the multi-scale modeling based on the mathematical homogenization theory without any phenomenological constitutive models such as kinematic hardening. Although this peculiar mechanical behavior was discovered in 19th century, and has been introduced as one of the most typical plastic phenomena for metals in most of basic textbooks for plasticity, the study of this mechanism has been superficial so for. First, we conduct experiments under cyclic loading for specimens with two kinds of microstructures; the pearlite and the spheroidized cementite structures. Then, these experiments exhibiting the Bauschinger effect are simulated by the global-local analysis technique. By focusing our attention to the micro-scale mechanical behavior, we try to explain why and how the effect comes out in experiments.
Microstructure-based evaluation of the influence of woven architecture on permeability by asymptotic homogenization theory Peer-reviewed

N Takano, M Zako, T Okazaki, K Terada

COMPOSITES SCIENCE AND TECHNOLOGY　62　(10-11)　1347-1356　2002

DOI： 10.1016/S0266-3538(02)00076-3 　

ISSN： 0266-3538
界面剥離を考慮した弾塑性複合材料のマルチスケール解析 Peer-reviewed

松井和己, 寺田賢二郎

JSCE Jouranal of Applied Mechanics　5　227-234　2002
Publisher:
DOI： 10.2208/journalam.5.227 　

ISSN： 1345-9139
マルチスケールモデリングに基づく非均質脆性材料の強度評価 Peer-reviewed

浅井光輝, 寺田賢二郎

JSCE Jouranal of Applied Mechanics　5　217-226　2002
Publisher:
DOI： 10.2208/journalam.5.217 　

ISSN： 1345-9139
炭素鋼の微視構造が巨視的な降伏・加工硬化特性に与える影響 Peer-reviewed

松井和己, 寺田賢二郎, 秋山雅義, 久保木孝, 日下桂一, 及川兼司

JSCE Jouranal of Applied Mechanics　5　175-183　2002
Publisher:
DOI： 10.2208/journalam.5.175 　

ISSN： 1345-9139
ポテンシャルを有する離散体のマルチスケールモデリング Peer-reviewed

菅家茂理, 斉木功, 中島章典, 寺田賢二郎, 池田清宏

JSCE Jouranal of Applied Mechanics　5　167-173　2002
Publisher:
DOI： 10.2208/journalam.5.167 　

ISSN： 1345-9139
階層型解析手法に基づく構造物の動的解析手法の開発 Peer-reviewed

市村強, 生出佳, 寺田賢二郎, 堀宗朗

JSCE Jouranal of Applied Mechanics　5　535-541　2002
Publisher:
DOI： 10.2208/journalam.5.535 　

ISSN： 1345-9139
圧縮場における弾塑性体の分岐解析とパスジャンプ挙動 Peer-reviewed

山川優樹, 寺田賢二郎, 池田清宏, 鳥居邦夫

土木学会論文集III　701　(III-58)　73-86　2002
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2002.701_73 　

ISSN： 0289-7806

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Bifurcation phenomena of initially homogeneous elasto-plastic specimen under uniform compression are numerically investigated. The finite strain, associated, strain hardening Drucker-Prager plasticity model is employed as a material model. Deformation of the specimen remains uniform on the primary equilibrium path, whereas non-uniform deformation modes arise due to bifurcation. We carry out several numerical analyses for bifurcation modes and post-bifuraction behavior without imposing initial imperfections, and show that diffuse bifurcation modes are one of the important factors for the occurrence of localized deformations. We also discuss the numerical results of path jumping phenomena.
Appropriate number of unit cells in a representative volume element for micro-structural bifurcation encountered in a multi-scale modeling Peer-reviewed

Saiki, I, K Terada, K Ikeda, M Hori

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING　191　(23-24)　2561-2585　2002

DOI： 10.1016/S0045-7825(01)00413-3 　

ISSN： 0045-7825
カキ殻混合土の非排水せん断強度・変形特性 Peer-reviewed

李基豪, 風間基樹, 寺田賢二郎

土木学会論文集III　701　(III-58)　303-314　2002
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2002.701_303 　

ISSN： 0289-7806

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In order to utilize mass of oyster shells for a partial substitute material for reclamation, we investigate the undrained shear characteristics of dredged sludge mixed with oyster shells by tri-axial compression test and numerical analysis based upon the mathematical homogenization. The following conclusions can be obtained from this study. It is verified that the shear strength of dredged clay is improved by mixing with oyster shells. The increase of the undrained shear strength is almost proportional for mixing rate (0-80%) of the oyster shell, and it is independent of consolidation stress (49-98kPa). And, it was guessed that the structure of the oyster shell in mixed soil complicatedly changed from stress-strain relationship and pore water pressure generation characteristic in proportion to the consolidation stress, oyster shell mixing rate, and the shear strain level.
Recursive bifurcation of tensile steel specimens Peer-reviewed

K Ikeda, S Okazawa, K Terada, H Noguchi, T Usami

INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE　39　(17)　1913-1934　2001/11

DOI： 10.1016/S0020-7225(01)00040-4 　

ISSN： 0020-7225
Parallelized two-scale analysis with a PC cluster for elastic-plastic heterogeneous media Peer-reviewed

Kazumi Matsui, Kenjiro Terada, Kohei Yuge

JSME International Journal, Series A: Solid Mechanics and Material Engineering　44　(4)　584-593　2001/10

DOI： 10.1299/jsmea.44.584 　

ISSN： 1344-7912
Esitmate of Macroscopci Yield Surface for the Elastic-Plastic Composite Materials Peer-reviewed

Kazumi Matsui, Kenjiro Terada, Takashi Kyoya, Tetsuo Iwakuma

Proceedings of JSCE　680　(I-56)　335-346　2001/07
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2001.682_335 　

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A method to a priori estimate the equivalent material behavior of the elastic-plastic heterogeneous bodies is developed within the frame work of the multi-scale modeling based on the mathematical homogenization theory. To estimate the macroscopic elastic-plastic properties, such as the macroscopic yield surface, we carry out a series of numerical experiments for the periodic microstructures called unit cells. Through its quantitative evaluation, the macroscopic initial yield surface is approximated by a quadratic function in the macroscopic stress space, and the evolution of the yield surface with anisotropic hardening is numerically investigated.
非線形均質化理論に基づく粒状体マルチスケ-ル解析法の開発とその応用 Peer-reviewed

金子賢治, 寺田賢二郎, 京谷孝史, 岸野佑次

土木学会論文集　III-55　(680)　183-199　2001/06
Publisher:
DOI： 10.2208/jscej.2001.680_183 　

ISSN： 0289-7806
マルチスケ-ル応力変形解析法とその分布亀裂を含む材料の強度特性評価への適用 Peer-reviewed

京谷孝史, 寺田賢二郎

土木学会論文集　III-55　(680)　49-64　2001/06
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2001.680_49 　

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A framework of the multiscale analysis method based on the mathematical homogenization theory is explored within the context of strength evaluation for fissured media. The two-scale variational formulation with appropriate functional setting plays a crucial role in our modeling for a general class of heterogeneous media. In particular, this modeling method for a fissured medium yields the microscopic variational inequality whereas the macroscopic problem is a standard equality. The formulation is utilized to propose the numerical strategy for evaluating its macroscopic strength and its feasibility is discussed by means of mathematical statements and through several numerical examples.
534 A study on the macroscopic elastic-plastic mechanical behavior of steel affected by its micro-structure

MATSUI Kazumi, OIKAWA Kenji, TERADA Kenjiro, AKIYAMA Masayoshi, KUBOKI Takashi

Proceedings of the 1992 Annual Meeting of JSME/MMD　2001　549-550　2001
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmezairiki.2001.0_549 　
Meso-scopic concrete analysis with a lattice model Peer-reviewed

M Asai, K Terada, K Ikeda

FRACTURE MECHANICS OF CONCRETE STRUCTURES, VOLS 1 AND 2　757-764　2001
Numerical multi-scale modeling and analysis of granular media based on the homogenization theory Peer-reviewed

K Kaneko, Y Kishino, T Kyoya, K Terada

POWDERS AND GRAINS 2001　169-172　2001
Two-Scale analysis of rock-like material body with cracks

T. Kyoya, H. Nishioka, K. Terada

6th U. S. National Congress on Computaional Mechanics, Abstracts　254　2001
Shape Effects of Necking Bifurcation in Tensile Steel Specimens Peer-reviewed

S.Okazawa, D.Terasawa, K.Ikeda, K.Terada

Proc.JSCE　675　(I-55)　351-354　2001
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2001.675_351 　

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The shape effects of tensile steel members, which stem from the complex bifurcation mechanism, are discussed from the engineering viewpoints. It is found that the aspect ratio affects the strength while the cross-sectional width-thickness ratio does the ductility. This kind of study provides insight into the evaluation of the mechanical property when the instability phenomena are involved.
有限変形を伴う構造物に対するconsistentトポロジー最適化手法 Invited Peer-reviewed

松井和己, 寺田賢二郎, 西脇眞二, 石橋義輝

日本計算工学会論文集(2001)，Paper No.20010046　2001
Development of Hybrid-FCM and its application to the analysis of interface fracture in multi-phase materials Peer-reviewed

Mitsuteru Asai, Kenjiro Terada, Kiyohiro Ikeda, Michihiro Yamagishi

JCSE Journal of Applied Mechanics　4　85-94　2001
Publisher:
DOI： 10.2208/journalam.4.85 　

ISSN： 1345-9139
A class of general algorithms for multi-scale analyses of heterogeneous media Peer-reviewed

K Terada, N Kikuchi

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING　190　(40-41)　5427-5464　2001

DOI： 10.1016/S0045-7825(01)00179-7 　

ISSN： 0045-7825
Three-dimensional evaluation of permeability of fiber reinforced composite materials based on their microstructures Peer-reviewed

N. Takano, K. Terada, M. Zako

Zairyo/Journal of the Society of Materials Science, Japan　50　(5)　488-494　2001
Publisher: Society of Materials Science Japan
DOI： 10.2472/jsms.50.488 　

ISSN： 0514-5163
有限変形を考慮したconsistentトポロジー最適化手法 Peer-reviewed

松井和己, 寺田賢二郎, 西脇眞二, 石橋慶輝

No.20010046　2001
Estimate of Microstructural Periodicity in Multi-scale Modeling for Macroscopic Material Instability based on the Block-diagonalization Method Peer-reviewed

Isao SAIKI, Kenjiro TERADA, Muneo HORI, Kiyohiro IKEDA

JSCE Journal of Applied Mechanics　3　37-45　2000/09
Publisher:
DOI： 10.2208/journalam.3.37 　

ISSN： 1345-9139
Multi-scale modeling for cellular solids with Frame Element Peer-reviewed

Ken OOUE, Isao SAKI, Akinori NAKAJIMA, Kenjiro TERADA

JSCE Journal of Applied Mechanics　3　185-192　2000/09

DOI： 10.2208/journalam.3.185 　
Permeability Characteristics of Dredged Sluges Mixed with Crashed Oyster Shell Peer-reviewed

Kiho LEE, Motoki KAZAMA, Kenjiro TERADA, Eiji YANAGISAWA

Journal of JSCE　III　(652)　245-256　2000/06
Publisher:
DOI： 10.2208/jscej.2000.652_245 　

ISSN： 0289-7806
Kinematically correct formulation for two-scale finite deformation problems Peer-reviewed

Kenjiro TERADA, Isao SAIKI, Kazumi MATSUI

Trans. JSCES　2　53-62　2000/05
Micro-macro modeling of nonlinear mechanical behaviors based on the homogenization theory Peer-reviewed

Kenjiro Terada, Kazumi Matsui, Atsushi Mano

Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A　66　(643)　516-523　2000
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.66.516 　

ISSN： 0387-5008
Simulation of the multi-scale convergence in computational homogenization approaches Peer-reviewed

Kenjiro Terada, Muneo Hori, Takashi Kyoya, Noboru Kikuchi

International Journal of Solids and Structures　37　(16)　2285-2311　2000
Publisher: Elsevier Ltd
DOI： 10.1016/S0020-7683(98)00341-2 　

ISSN： 0020-7683
Evaluation of Permeability of Resin in Textile Composites by the Homogenization Method Peer-reviewed

Naoki TAKANO, Kenjiro TERADA, Masaru ZAKO, Tomomi YOSHIOKA

Trans. JSCM　26　(5)　171-178　2000
Publisher: JAPAN SOCIETY FOR COMPOSITE MATERIALS
DOI： 10.6089/jscm.26.171 　

ISSN： 0385-2563

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The liquid composite molding process involves the coupling between the mechanical behaviors of solids and fluids. To simulate such a process, the evaluation of the permeability is indispensable, while most of previous researches are based on the experimental approach. On the other hand, this paper adopts the mathematical theory of homogenization, which is suitable to numerical analysis. After describing the formulation of the homogenization for solid-fluid mixture, the permeabilities of typical textile composites have been evaluated with the help of the finite element method. Due to the micro-macro features of the method, the consideration of the complex microstructures of knit, woven and "Kumi" cloth has led to not only the three-dimensionally anisotropic permeabilities, but also the characteristic microscopic velocity distribution of the fluids.
A Generalized Algorithm for Multi-scale Analysis of Heterogeneous Elastic-Plastic Bodies Peer-reviewed

Kenjiro TERADA, Noboru KIKUCHI

Journal of JSCE　I　(633)　217-229　1999/10

DOI： 10.2208/jscej.1999.633_217 　
Evaluation of Deformability and Strength of Rock Mass using Properties of Intact Rocks and Digital Image of Crack Distribution Peer-reviewed

Takashi KYOYA, Kenjiro TERADA, Lizhu OYANG

Journal of JSCE　III　(631)　131-150　1999/09
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.1999.631_131 　

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Mechanical properties of rock mass are strongly governed by the microscopic structure that consists of distributed cracks and various rock materials. In order to evaluate the deformability and the strength of such a rock mass, the numerical scheme of multi-scale which is based on both the homogenization method and the limit load analysis is proposed. The data needed are only the mechanical properties of intact rocks and the digital image of crack distribution, which are easily obtained from laboratory tests and survey in site. The deformability and strength of representative element of rock mass are reasonably evaluated from the homogenization analyses. And then the limit load of a rock mass structure is also successfully evaluated by the limit load analysis.
On Evaluation of the Mechanical Property of Composite Material by the Homogenization Method Peer-reviewed

Takashi KYOYA, Kenjiro TERADA, Lizhu OYANG, Hidetoshi NISHIOKA

JSCE Journal of Applied Mechanics　2　449-459　1999/09
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalam.2.449 　

ISSN： 1345-9139

eISSN： 1884-832X

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A numerical scheme to evaluate the elastic stiffness and strength of heterogeneous material, which have been proposed by authors based on the theory of homogenization, is applied to fiber reinforced composites, and its validity for evaluating their mechanical properties is examined. Results show that the numerical scheme can give fairly good predictions as for the elastic stiffness, but it can only predicts value of strength near to the experimental data since the numerical scheme does not take the existence of initial defects in the composites into account. However, it can conclude that our proposed method can use for evaluation of mechanical property of composite material at some first stage of design since the method needs only the mechanical properties of each materials of which the composite consists and a graphical data representingthe geometric feature of the composite structure.
Multi-scale Problems with Buckling for Multi-scale Analysis of Cellular Solids Peer-reviewed

Isao SAIKI, Kenjiro TERADA, Kiyohiro IKEDA

JSCE Journal of Applied Mechanics　2　(2)　287-294　1999/09
Publisher:
DOI： 10.2208/journalam.2.287 　

ISSN： 1345-9139
Multi-scale limit load analysis for discontinuous rock mass based on the homogenization method Peer-reviewed

T Kyoya, K Terada, T Kawamoto

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS　23　(10)　995-1019　1999/08

DOI： 10.1002/(SICI)1096-9853(19990825)23:10<995::AID-NAG21>3.0.CO;2-B 　

ISSN： 0363-9061
Optimal Design of Golf Club using Multibody Dynamics Peer-reviewed

Hideomi OHTSUBO, Katsuyuki SUZUKI, Kenjiro TERADA, Daisuke KOBAYASHI

Trans. JSCES　1　(1)　95-100　1999/05
Publisher:
ISSN： 1344-9443
Numerical Solutions of Multi-scale Structural Analysis for Elastoplastic Bodies Peer-reviewed

Kenjiro TERADA, Kazumi MATSUI

Trans. JSCES　1　75-82　1999/05
Method of Multiscale Analysis for a Medium with Infinitely Many Fissures Peer-reviewed

kenjiro TERADA, Takashi Kyoya

Journal of JSCE　619　(I-47)　23-33　1999/04
Publisher:
DOI： 10.2208/jscej.1999.619_23 　

ISSN： 0289-7806
An Evaluation Method of Macroscopic Shape of Defects in Microscopically Inhomogeneous Materials Peer-reviewed

Kenjiro TERADA, Kazuyuki NAKAHATA, Michihiro KITAHARA

Trans. JSME(A)　65　(631)　138-145　1999/03
Bifurcation mechanism underlying echelon-mode formation Peer-reviewed

K Murota, K Ikeda, K Terada

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING　170　(3-4)　423-448　1999/03

DOI： 10.1016/S0045-7825(98)00206-0 　

ISSN： 0045-7825
Limit load analysis of rock mass structure with consideration to microscopic local stress with a homogenization method Peer-reviewed

T Tsuruhara, T Tokunaga, T Osada, T Kyoya, K Terada, L Oyang

NINTH INTERNATIONAL CONGRESS ON ROCK MECHANICS, VOLS 1 & 2　527-530　1999
Stability analysis of discontinuous rock mass by homogenization method

T. Kyoya, K. Terada, L. Oyang

Proc. 2nd Chine-Japan Jopint Symp. Recent Development of Theory and Practice in Geotechnology　209-216　1999
Stochastic Evaluation Method for Elastic Buckling Strength of Truss Structures Peer-reviewed

菅野友紀, 浅井光輝, 池田清宏, 寺田賢二郎, 小田憲史

JSCE Journal of Applied Mechanics　2　(2)　37-42　1999
Publisher:
DOI： 10.2208/journalam.2.37 　

ISSN： 1345-9139
Image Analysis of Shear Bands on Kaolin by Bifurcation Theory Peer-reviewed

Isao SAIKI, Shinya MURAKAMI, Ikuo SANO, Kiyohiro IKEDA, Kenjiro TERADA

JSCE Journal of Applied Mechanics　1　15-22　1998/08

DOI： 10.2208/journalam.1.15 　
The Meshless analysis of Solid Structure using Voxel Cover Peer-reviewed

Katsuyuki SUZUKI, Hideomi OHTSUBO, Kenjiro TERADA, Seunjae MIN, Denei KIN, Katsuyoshi NAKANISHI

JSCE Journal of Applied Mechanics　1　(1)　215-222　1998/08
Publisher:
DOI： 10.2208/journalam.1.215 　

ISSN： 1345-9139
Visco-elastic analysis of asphalt concrete based on homogenization theory using Laplace transform Peer-reviewed

Tomoyuki UO, Kazuo KASHIYAMA, Kenjiro TERADA

JSCE Journal of Applied Mechanics　1　(1)　195-202　1998/08
Publisher:
DOI： 10.2208/journalam.1.195 　

ISSN： 1345-9139
Application of the homogenization Method to beam member with periodic structures Peer-reviewed

Takashi KYOYA, Kenjiro TERADA

JSCE Journal of Applied Mechanics　1　(1)　185-194　1998/08
Publisher:
DOI： 10.2208/journalam.1.185 　

ISSN： 1345-9139
Multi-scale analyis modeling for heterogeneous media Peer-reviewed

kenjiro TERADA, Muneo Hori, Takashi Kyoya

JSCE Journal of Applied Mechanics　1　177-183　1998/08

DOI： 10.2208/journalam.1.177 　
Application of the homogenization method to beam member with periodic structures Peer-reviewed

Takashi KYOYA, Kenjiro TERADA

Journal of Applied Mechanics JSCE　1　185-194　1998

DOI： 10.2208/journalam.1.185 　
Multi-scale analysis modelling for heterogeneous media Peer-reviewed

寺田賢二郎, 堀宗朗, 京谷孝史

Journal of Applied Mechanics JSCE　1　177-184　1998

DOI： 10.2208/journalam.1.177 　
Viscoelastic Constitutive Law as an Asymptotic Behavior in the Homogenization Method for Solid-Fluid Mixture Peer-reviewed

Kenjiro TERADA, Takashi ITO, Noboru Kikuchi

Journal of JSCE　591　(I-43)　99-109　1998
Publisher:
DOI： 10.2208/jscej.1998.591_99 　

ISSN： 0289-7806
A Study of the Homogenization Method for Solid-Fluid Mixtures from Engineering Viewpoints Peer-reviewed

Kenjiro TERADA, Takashi ITO, Noboru Kikuchi

Journal of JSCE　591　(I-43)　85-97　1998
Publisher:
DOI： 10.2208/jscej.1998.591_85 　

ISSN： 0289-7806
Microstructural Modeling Technique for Homogenization Analysis using Digital Images Peer-reviewed

Kenjiro TERADA, Noboru Kikuchi

Trans. JSME(A)　64　(617)　170-177　1998
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.64.170 　

ISSN： 0387-5008

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A systematic modeling technique of utilizing digitized images for micromechanical analysis in the asymptotic homogenization method is presented. By use of digital images, irregular material configurations are accurately modeled for the material pre/post-processing and therefore the specific microstructural geometry is taken into account in evaluation of the micro and macroscopic variables. Each picture element (pixel) in the images is identified with a regular and fixed-size finite element, and a three-dimensional (3 D) unit cell model can be generated by stacking of two-dimensional (2 D) images into a 3 D image consisting of volume picture elements (voxels). After the concrete modeling procedure is presented, its applicability to the analysis and advantages from a computational point of view are discussed. With a very primitive unit cell model that is generated using digital images, the numerical accuracy in homogenization analyses is investigated and some practical aspects of its usage are identified. Furthermore, several applications are presented in order to show the rigorousness and the flexibility of this modeling technique in terms of the pixel (or voxel) information and image manipulations.
Application of the Asymptotic Homogenization Method for Composites with Irregular Material Configurations Peer-reviewed

Kenjiro TERADA, Noboru Kikuchi

Trans. JSME(A)　64　(617)　162-169　1998

DOI： 10.1299/kikaia.64.162 　
Characterization of the mechanical behaviors of solid-fluid mixture by the homogenization method Peer-reviewed

K Terada, T Ito, N Kikuchi

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING　153　(3-4)　223-257　1998/01

DOI： 10.1016/S0045-7825(97)00071-6 　

ISSN： 0045-7825
FFT-based homogenization algorithm using digital images Peer-reviewed

K Terada, K Suzuki, H Ohtsubo

MATERIALS SCIENCE RESEARCH INTERNATIONAL　3　(4)　231-236　1997/12

DOI： 10.2472/jsms.46.12Appendix_231 　

ISSN： 1341-1683
Analsys Method of Solid Structures using Voxel Information Peer-reviewed

Katsuyuki SUZUKI, Kenjiro TERADA, Hideomi OHTSUBO, Naoki Yonesato

Trans. SNAJ　182　(182)　595-600　1997/11
Publisher: The Japan Society of Naval Architects and Ocean Engineers
DOI： 10.2534/jjasnaoe1968.1997.182_595 　

ISSN： 0514-8499

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In the analysis of 3 dimensional solid structure, the mesh generation is always the most time consuming task and sometimes it make the analysis impossible. In this paper, the mesh generation method combined with the analysis method is considered, which digitize the 3D solid objects into voxel data, and uses the voxel data as a finite element mesh. Although this approach makes the finite element mesh generation for the solid structure with quite complicated configuration easy, it was shown that it gives artificial high stress elements around the boundary, which is resulted from the zigzag shaped boundary. Also the voxel analysis makes the number of freedom to be used in the analysis huge, and although the computational cost of analysis model generation is low, computational cost of analysis itself becomes huge. The alternative analysis method based on the multi-scale voxel data, which defines different resolution for geometric model and analysis model on the boundary are proposed. It was shown that this model gives more accurate element stiffness matrix on the boundary and gives more accurate results than conventional voxel analysis. Several examples are shown, and it was demonstrated that this analysis method reduces the whole throughput. time of the analysis of solid structure.
Digital image-based modeling applied to the homogenization analysis of composite materials Peer-reviewed

K Terada, T Miura, N Kikuchi

COMPUTATIONAL MECHANICS　20　(4)　331-346　1997/09

DOI： 10.1007/s004660050255 　

ISSN： 0178-7675
Evaluation of mechanical property of cracked rock mass by homogenization method and limit load analysis Peer-reviewed

Takashi Kyoya, Kenjiro Terada, Yuji Kishino

Proceedings of the 42nd Symposium on Geotechnical Engineering　87-92　1997/08
Macro and micro scale modeling of thermal residual stresses in metal matrix composite surface layers by the homogenization method Peer-reviewed

D Golanski, K Terada, N Kikuchi

COMPUTATIONAL MECHANICS　19　(3)　188-202　1997/02

DOI： 10.1007/s004660050168 　

ISSN： 0178-7675
Limit load analysis of rock mass structures combined with a homogenization method Peer-reviewed

T Kyoya, K Terada, Y Kishino

DEFORMATION AND PROGRESSIVE FAILURE IN GEOMECHANICS - IS-NAGOYA'97　407-412　1997
Stability analysis of rock mass structures based on a homogenization method and a limit load analysis Peer-reviewed

T Kyoya, K Terada, Y Kishino, T Kawamoto

COMPUTER METHODS AND ADVANCES IN GEOMECHANICS, VOL 1　337-342　1997
Global/local constitutive modeling of composite materials by the homogenization method Peer-reviewed

K Terada, N Kikuchi

MATERIALS SCIENCE RESEARCH INTERNATIONAL　2　(2)　73-80　1996/06

DOI： 10.2472/jsms.45.6Appendix_73 　

ISSN： 1341-1683
Microstructural design of composites using the homogenization method and digital images Peer-reviewed

K Terada, N Kikuchi

MATERIALS SCIENCE RESEARCH INTERNATIONAL　2　(2)　65-72　1996/06

DOI： 10.2472/jsms.45.6Appendix_65 　

ISSN： 1341-1683
Elasto-Plastic Analysis of Composite Materials using the Homogenization Method (2nd Report, Numerical Analysis) Peer-reviewed

Kenjiro TERADA, Kohei YUGE, Noboru Kikuchi

Trans. JSME(A)　62　(601)　2072-2079　1996
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.62.2072 　

ISSN： 0387-5008

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Homogenization formulae were developed for predicting the elastoplastic mechanical behavior of composite materials in a previous work. The nonlinear solution method for the finite element method makes it possible to compute the microscopic and the macroscopic deformations simultaneously, both of which reveal large deformations, and then accumulate the incremental solutions successively. The macroscopic deformation can be obtained by averaging the microscopic stress/strain state in each constituent, without a priori knowing an averaged stress-strain relation from experiments. Several numerical examples are presented to verify the formulation and to illustrate the three-dimensional nature in global-local simultaneous computation (G. -L. S. C.). The method is also applied to the analysis of interfacial damage of nonmetallic composite materials. The computational aspects of the nonlinear homogenization method are briefly discussed.
Elasto-Plastic Analysis of Composite Materials using the Homogenization Method (1st Report, Formulation) Peer-reviewed

Kenjiro TERADA, Kohei YUGE, Noboru Kikuchi

Trans. JSME(A)　61　(590)　2199-2205　1995

DOI： 10.1299/kikaia.61.2199

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Misc. 302

3次元流れ実験による慣性力評価のための樹木の「かたち」のモデル化—Trees geometry modeling for 3D numerical flow tests on its inertial force effects

野村怜佳, 石澤/修司, 森口周二, 寺田賢二郎

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　29　1356-1359　2024/06
Publisher: 東京 : 日本計算工学会
斜面安定解析への量子アニーリングの適用性の検討—Application of Quantum Annealing to Slope Stability Analysis

外里健太, Xiao Junsen, 須郷大地, 山内翔太, 野村怜佳, 森口周二, 高瀬慎介, 金子賢治, 寺田賢二郎

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　29　947-950　2024/06
Publisher: 東京 : 日本計算工学会
DBSCANを援用した極限平衡理論に基づく広域三次元斜面安定解析—Large-area Three-dimensional Slope Stability Analysis based on Limit Equilibrium Theory with the Aid of DBSCAN

須郷大地, 藤田真粹, Nilo DOLOJAN, 外里健太, 野村怜佳, 森口周二, 寺田賢二郎

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　29　1023-1028　2024/06
Publisher: 東京 : 日本計算工学会
三次元極限平衡理論に基づく広域斜面安定解析—Wide-area Slope Stability Analysis based on Limit Equilibrium Theory

須郷大地, 藤田真粹, 外里健太, 野村怜佳, 森口周二, 寺田賢二郎

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　28　404-408　2023/05
Publisher: 日本計算工学会
落石形状特性が到達分布に与える影響のモデル化—Modeling the Influence of Rock Shape on Run-out distribution of Rockfall

吉田大活, 野村怜佳, 森口周二, 寺田賢二郎, 津田悠人, 吉田郁政

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　28　1299-1301　2023/05
Publisher: 日本計算工学会
非Darcy流れにおける透水性低下特性に関する数値解析的検討—A Numerical Study on the Characterization of Permeability Reduction in Non-Darcy Flows

一藤亮太, 橘一光, 野村怜佳, 高瀬慎介, 森口周二, 寺田賢二郎

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　28　368-372　2023/05
Publisher: 日本計算工学会
ロバスト主成分分析に基づく沖合津波観測点配置の最適化—Optimization of Offshore Gauge Configuration with Robust Principal Component Analysis

藤田真粹, 野村怜佳, 大竹雄, 越村俊一, 森口周二, 寺田賢二郎

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　28　79-82　2023/05
Publisher: 日本計算工学会
多様なシナリオデータベースの融合による津波リスク同定—Tsunami risk evaluation by the combined use of heterogenous datasets

野村怜佳, 大竹雄, 森口周二, 越村俊一, Randall J. LeVeque, 寺田賢二郎

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　28　83-86　2023/05
Publisher: 日本計算工学会
斜面安定解析結果を用いた豪雨による広域斜面崩壊の即時予測—Rapid prediction of rainfall-induced landslides for a wide area using slope stability analysis results

外里健太, 野村怜佳, 森口周二, 寺田賢二郎

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　28　63-68　2023/05
Publisher: 日本計算工学会
降雨の不確実性を考慮した斜面安定解析による土砂災害ハザードマップの構築—Landslide Hazard Mapping Based on Slope Stability Analysis Considering Rainfall Uncertainty

外里健太, 佐々木駿, 森口周二, 寺田賢二郎

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　27　1003-1006　2022/06
On reasonable observation periods in the sequential real-time tsunami risk assessment based on POD technique

VERMARE Louise A. Hirao, FUJITA Saneiki, NOMURA Reika, OTAKE Yu, MORIGUCHI Shuji, TERADA Kenjiro, LEVEQUE Randall J.

計算工学講演会論文集(CD-ROM)　27　2022

ISSN： 1342-145X
Evaluation of Forces Acting on Behind Structures by Rigid Drifting Objects Using Three-Dimensional Fluid-Structure Coupled Analysis

一藤亮太, 野村怜佳, 高瀬慎介, 森口周二, 寺田賢二郎

計算工学講演会論文集(CD-ROM)　27　2022

ISSN： 1342-145X
Gauge Configuration Optimization for Real-time Tsunami Forecast with POD

藤田真粹, 野村怜佳, 越村俊一, 大竹雄, 森口周二, 寺田賢二郎, 高瀬慎介, 福谷陽, 桜庭雅明, 野島和也, 橋詰正広

計算工学講演会論文集(CD-ROM)　27　2022

ISSN： 1342-145X
Realtime tsunami risk estimation approach development using particle filter

26　487-490　2021/06
Publisher: 日本計算工学会
固有直交分解を用いたリアルタイム津波シミュレーション—Real-time tsunami simulation using Proper Orthogonal Decomposition

外里健太, 高瀬慎介, 森口周二, 寺田賢二郎, 大竹雄, 福谷陽, 野島和也, 櫻庭雅明, 横洲弘武

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　25　6p　2020/06
Publisher: 日本計算工学会
三陸沖北部地震を考慮した八戸市における X-GISを用いた津波遡上解析

中村優真, 高瀬慎介, 野島和也, 櫻庭雅明, 山口裕矢, 森口周二, 寺田賢二郎

東北地域災害科学研究　56　179-182　2020/03
Road Slope Risk Assessment and Optimal Allocation of Protection Structures Using Rockfall Simulation

菅野蓮華, 森口周二, 寺田賢二郎, 林俊介, 磯部有作, 吉田郁政

計算工学講演会論文集(CD-ROM)　24　ROMBUNNO.B‐11‐03　2019/06/29

ISSN： 1342-145X
数値解析結果の空間モード分解による津波のリスク評価—Tsunami risk assessment using spatial modes extracted from results of numerical analysis

外里健太, 小谷拓磨, 森口周二, 寺田賢二郎, 大竹雄

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　24　4p　2019/05
Publisher: 日本計算工学会
Decoupled Multi-scale Analysis of FRP in Consideration for Dependency of Resin's Properties on Degree of Cure

齋藤理沙, 山口裕矢, 森口周二, 三原康子, 小林卓哉, 寺田賢二郎

計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science　24　2019/05
Publisher: 日本計算工学会
Estimation of impact force acting on structures caused by sediment movement using Material Point Method

吉田昂平, 山口裕矢, 森口周二, 寺田賢二郎

計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science　24　2019/05
Publisher: 日本計算工学会
地盤流動化の数値解析を目的としたMPMの提案と適用性の検討

山口裕矢, 高瀬慎介, 森口周二, 寺田賢二郎

計算工学講演会論文集　24　B-05-04　2019/05
二次元広域流れにおける樹木抵抗評価のための三次元数値実験手法

野村怜佳, 高瀬慎介, 森口周二, 寺田賢二郎

計算工学講演会論文集　24　B-05-05　2019/05
An evaluation of spatial risk distribution of snow avalanche using 3D simulation and empirical formula of impact force

鬼頭昂平, 菅野蓮華, 小谷拓磨, 森口周二, 寺田賢二郎, 中村一樹, 上石勲

計算工学講演会論文集(CD-ROM)　24　2019

ISSN： 1342-145X
Determination of macroscopic viscoelastic properties as well as macroscopic thermal deformation and cure-shrinkage properties of fiber reinforced plastics in consideration of cure process

SAITO Risa, YAMAGUCHI Yuya, MORIGUCHI Shuji, MIHARA Yasuko, KOBAYASHI Takaya, TERADA Kenjiro

Transactions of the JSME (in Japanese)　85　(870)　18-00396-18-00396　2019
Publisher: The Japan Society of Mechanical Engineers

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This study presents a method of determining the macroscopic viscoelastic properties as well as the macroscopic coefficients of thermal expansion and cure-shrinkage of fiber-reinforced plastics (FRP) in consideration of the dependence of the viscoelastic properties of the resin used in the matrix phase on the degree of cure (DOC). The DOC-dependent viscoelastic material behavior of the resin is represented by the generalized Maxwell model and is accompanied with non-mechanical strains such as thermal strain and cure shrinkage. Within the framework of computational homogenization, a series of numerical material tests (NMTs) are conducted on a representative volume element (microstructure) with different DOCs to discretely evaluate the macroscopic viscoelastic properties. On the assumption that the macroscopic material behavior can be represented by the anisotropic version of the generalized Maxwell model, we originally propose a method to determine the macroscopic viscoelastic properties and the macroscopic coefficients of thermal expansion and cure-induced shrinkage, both of which are functions of DOC. After numerical examples to determine these properties for a specific unit cell of FRP are presented, a simple numerical verification is carried out to demonstrate that the proposed method is capable of determining the DOC-dependent macroscopic viscoelastic properties associated with mechanical and non-mechanical strains.
水素の非定常拡散を考慮した水素助長疲労き裂の進展解析

石橋奏, 新宅勇一, 寺田賢二郎, 堤成一郎

溶接学会全国大会講演概要(Web)　2018　(103)　68‐69(J‐STAGE)-69　2018/09
Publisher: 一般社団法人溶接学会

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本研究では，水素環境下において繰り返し載荷を受ける金属材料の寿命評価を行うために，水素の非定常拡散と水素助長疲労き裂進展の相互作用を考慮した弱連成解析手法を構築した．具体的には，き裂面からの水素流入を評価し，水素脆化と疲労損傷による材料の強度低下を考慮した結合力モデルを採用した．最後に，繰り返し載荷の振幅や周波数を変化させた数値解析例を通して，構築した解析手法の性能について検証した．
An evaluation method of spatial risk distribution based on 3D snow avalanche simulation

鬼頭昂平, 小谷拓磨, 山口裕也, 森口周二, 寺田賢二郎, 小田憲一, 上石勲

計算工学講演会論文集(CD-ROM)　23　ROMBUNNO.B‐08‐06　2018/06/06
Publisher: 日本計算工学会
ISSN： 1342-145X
Damage assessment of structural steel for effects of different loading conditions and stress triaxiality using elastoplastic model with isotropic and kinematic hardening

副島克哉, 新宅勇一, 堤成一郎, 寺田賢二郎

計算工学講演会論文集(CD-ROM)　23　ROMBUNNO.E‐10‐05　2018/06/06
Publisher: 日本計算工学会
ISSN： 1342-145X
A method for seamless transition from material degradation to crack propagation

新宅勇一, 寺田賢二郎, 堤成一郎

計算工学講演会論文集(CD-ROM)　23　ROMBUNNO.E‐10‐03　2018/06/06
Publisher: 日本計算工学会
ISSN： 1342-145X
Numerical evaluation of viscous dissipation for flow involving coastal forest

23　3p　2018/06
Publisher: 日本計算工学会
Development of solid-liquid mixture MPM and its application to deformation and flow analysis of soil

山口裕矢, 高瀬慎介, 森口周二, 寺田賢二郎

計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science　23　2018/06
Publisher: 日本計算工学会
Multiscale simulation of FRP considering cure shrinkage of resin

齋藤理沙, 山口裕矢, 森口周二, 寺田賢二郎, 三原康子, 小林卓哉

計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science　23　2018/06
Publisher: 日本計算工学会
Effects of material properties and particle shape characteristics on repose angle

奥山大輝, 橘一光, 寺田賢二郎, 森口周二, 青木尊之

計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science　23　2018/06
Publisher: 日本計算工学会
Fatigue lifetime prediction of structural steel by cohesive-traction embedded elasto-plastic damage model with kinematic hardening

SOEJIMA Katsuya, SHINTAKU Yuichi, TSUTSUMI Seiichiro, TERADA Kenjiro

The Proceedings of The Computational Mechanics Conference　2018　(0)　2018
Publisher: The Japan Society of Mechanical Engineers

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The objective of this study is to predict the fatigue lifetime of structural steel using cohesive-traction embedded elasto-plastic damage model with kinematic hardening. By the cohesive-traction embedded damage model, the elasto-plastic model is combined by introduction of local equilibrium conditions between principal stress and cohesive traction to realize actual crack opening displacement during cyclic loading. Whereas the cohesive zone model proposed by Rice and Wang is utilized with consideration of unloading process, an isotropic and kinematic hardening in the elasto-plastic model is represented by Voce and Chaboche model, respectively. Moreover, an experiment is also conducted with a round notched bar under the cyclic loading condition controlled by a constant amplitude of plastic strain. By the comparison between the numerical and the experimental result, it is confirmed that the proposed model can represent both two kinds of the hardening behavior and predict the fatigue lifetime under cyclic loading.
Statistical modeling for evaluating the optimal placement of rockfall protection structures on a road

Hasuka Kanno, Shuji Moriguchi, Kenjiro Terada, Shunsuke Hayashi, Yusaku Isobe, Shoji Iwanaga

Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM))　74　(2)　I_13-I_21　2018
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejam.74.i_13 　

eISSN： 2185-4661
Micro-texture design and optimization in hydrodynamic lubrication via two-scale analysis Peer-reviewed

A. Waseem, I. Temizer, J. Kato, K. Terada

STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION　56　(2)　227-248　2017/08

DOI： 10.1007/s00158-017-1713-5 　

ISSN： 1615-147X

eISSN： 1615-1488
非構造格子を用いた実地形を考慮した雪崩の流動解析

山口裕矢, 高瀬慎介, 森口周一, 寺田賢二郎, 上石勲

計算工学講演会論文集(CD-ROM)　22　ROMBUNNO.C‐09‐4　2017/05/31
Publisher: 日本計算工学会
ISSN： 1342-145X
A study on the suppression of CFRP static strength variation using data mining techniques

22　3p　2017/05
Publisher: 日本計算工学会
Multiscale simulation of LSCF with evolving ferroelastic phase

22　6p　2017/05
Publisher: 日本計算工学会
A Quantitative Evaluation Method for Effective Placement of Rockfall Countermeasures Based on a Numerical Simulation

22　3p　2017/05
Publisher: 日本計算工学会
Characterization of deformation properties of surface ground due to fault movement using finite-strain damage model

22　4p　2017/05
Publisher: 日本計算工学会
Evaluation of effect of carbon filler on rubber with a finite viscoelastic damage model

22　3p　2017/05
Publisher: 日本計算工学会
Numerical plate testing for non-elastic multi-scale analysis of plate-shaped device

22　6p　2017/05
Publisher: 日本計算工学会
Nonlinear structural analysis using coupled method of the homogenization and resin flow analysis for injection molding

22　4p　2017/05
Publisher: 日本計算工学会
Study on Destruction Prediction of Unidirectional Composite by Multi-Scale Analysis

22　4p　2017/05
Publisher: 日本計算工学会
The Role of General Purpose FE Codes in Computational Mechanics

22　3p　2017/05
Publisher: 日本計算工学会
Development of transient electrochemo-mechanical analysis system for solid oxide fuel cell

22　5p　2017/05
Publisher: 日本計算工学会
A proposal of evaluation method for tsunami loading including debris impact using surrogate model

22　3p　2017/05
Publisher: 日本計算工学会
Effects of uncertainties of slope in rockfall simulations

22　5p　2017/05
Publisher: 日本計算工学会
Fully coupled thermo-mechanical analysis of thermoplastic resins by incremental variational formulations

22　4p　2017/05
Publisher: 日本計算工学会
Modeling of Solid-Liquid Mixture for Fluid-Sediment Interaction Analysis

22　4p　2017/05
Publisher: 日本計算工学会
Numerical analysis on non-linear characteristic of permeability coefficient of geomaterial using fluid-particle-coupled simulation

橘一光, 森口周二, 高瀬慎介, 寺田賢二郎, 青木尊之, 神谷浩二, 小高猛司

計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science　22　4p　2017/05
Publisher: 日本計算工学会
Study for the comprehensive glass-rubber mechanical properties of thermoplastic resins by the viscoelastic-viscoplastic constitutive law

22　6p　2017/05
Publisher: 日本計算工学会
Experimental Study of thermoplastic resins for viscoelastic-viscoplastic constitutive law

22　5p　2017/05
Publisher: 日本計算工学会
Nonlinear finite element analysis considering crystal plasticity and mechanically induced martensite transformation

Sciichiro Tsutsumi, Fincato Riccardo, Kenjiro Terada

Yosetsu Gakkai Shi/Journal of the Japan Welding Society　86　(6)　443-447　2017
Publisher: Japan Welding Society
DOI： 10.2207/jjws.86.443 　

ISSN： 0021-4787
A simulation of ferroelastic phase formation by using phase-field model

M. Muramatsu, T. Kawada, K. Terada

Key Engineering Materials　725　208-213　2017
Publisher: Trans Tech Publications Ltd
DOI： 10.4028/www.scientific.net/KEM.725.208 　

ISSN： 1013-9826

eISSN： 1662-9795
Analysis system of transient Electrochemo-Mechanical simulation of solid oxide fuel cell implemented in commercial fem software

Masami Sato, Mayu Muramatsu, Kenjiro Terada, Satoshi Watanabe, Keiji Yashiro, Tatsuya Kawada, Harumi Yokokawa

Transactions of the Japan Society for Computational Engineering and Science　2017　2017/01/01

DOI： 10.11421/jsces.2017.20170004 　

eISSN： 1347-8826
Homogenization-based design of surface textures in hydrodynamic lubrication Peer-reviewed

A. Waseem, I. Temizer, J. Kato, K. Terada

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING　108　(12)　1427-1450　2016/12

DOI： 10.1002/nme.5256 　

ISSN： 0029-5981

eISSN： 1097-0207
へき開面における原子間分離に基づく異方性損傷構成則

新宅勇一, 寺田賢二郎, 堤成一郎

日本機械学会計算力学講演会論文集(CD-ROM)　29th　(0)　ROMBUNNO.171　2016/09/21
Publisher: 一般社団法人日本機械学会
災害予測シミュレーションの高度化とその見える化の試み : 計算災害科学の確立にむけて (安全・安心な生活とICT)

寺田賢二郎, 森口周二, 高瀬慎介

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報　116　(92)　63-72　2016/06/14
Publisher: 電子情報通信学会
ISSN： 0913-5685
延性破壊を考慮した結合力モデルとその結合力を埋め込んだ損傷構成則

新宅勇一, 寺田賢二郎, 堤成一郎

計算工学講演会論文集(CD-ROM)　21　ROMBUNNO.D‐4‐4　2016/05/31
Publisher: 日本計算工学会
ISSN： 1342-145X
個別要素法による実大規模土砂流動実験の再現解析—A simulation of a real-scale sediment flow experiment using DEM

森口周二, 太田勇真, 高瀬慎介, 寺田賢二郎, 阿部慶太, 青木尊之

計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会編　21　4p　2016/05
Publisher: 日本計算工学会
A simulation method for predicting firing deformation during of ceramics

21　3p　2016/05
Publisher: 日本計算工学会
A finite deformation damage model for multi-stage fracture simulations of concrete

21　4p　2016/05
Publisher: 日本計算工学会
Tsunami debris simulation using shallow water equations based on finite cover method

21　4p　2016/05
Publisher: 日本計算工学会
A Spatial and Probabilistic Risk Evaluation Method of Rockfalls Based on Discrete Element Method

21　6p　2016/05
Publisher: 日本計算工学会
Identification of Thermal Expansion Coefficients for CFRTP using Homogenization Technique

21　4p　2016/05
Publisher: 日本計算工学会
Evaluation of material constants and press forming simulation for dry fabric using homogenization technique

21　5p　2016/05
Publisher: 日本計算工学会
Multi-scale topology optimization based on decoupled thermal and structural analysis

21　5p　2016/05
Publisher: 日本計算工学会
Two-stage cohesive failure simulation with co-rotational formulation

21　4p　2016/05
Publisher: 日本計算工学会
Multiscale topology optimization for composite plates undergoing large displacement

21　4p　2016/05
Publisher: 日本計算工学会
Investigations of energy absorbing characteristics of thermoplastic resin and rubber-like materials

21　5p　2016/05
Publisher: 日本計算工学会
Simulations of Snow Avalanches Using Stabilized Finite Element Method

山口裕矢, 高瀬慎介, 森口周二, 寺田賢二郎

計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science　21　4p　2016/05
Publisher: 日本計算工学会
A Numerical Simulation of Grain-scale seepage flow of Geomaterials using Immersed Boundary Method

橘一光, 森口周二, 高瀬慎介, 寺田賢二郎, 神谷浩二, 小高猛司

計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science　21　4p　2016/05
Publisher: 日本計算工学会
The rheology based constitutive modeling for the amoprhous resin in the glassy-rubbery regions

21　4p　2016/05
Publisher: 日本計算工学会
High-precision measurements of resin materials by DIC, and modeling

21　5p　2016/05
Publisher: 日本計算工学会
個別要素法による実大規模土砂流動実験の再現解析

森口周二, 太田勇真, 高瀬慎介, 寺田賢二郎, 阿部慶太, 青木尊之

計算工学講演会論文集(CD-ROM)　21　2016

ISSN： 1342-145X
OS1316-242 Mechanical Simulation of The Microstructure in The Ferroelastic Material LSCF

MURAMATSU Mayu, TERADA Kenjiro, KAWADA Tatsuya

2015　"OS1316-242-1"-"OS1316-242-2"　2015/11/21
Publisher: The Japan Society of Mechanical Engineers

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In this paper, a model which represents the mechanical behavior is developed for the ferroelastic material, Lanthanum Strontium Cobalt Ferrite (LSCF), which is a ceramic material often used for a cathode of Solid Oxide Fuel Cell (SOFC). Nonelestic deformation analysis is performed to express the mechanical property of LSCF. At the same time phase transformation of ferroelasticity is analyzed by the use of phase-field model based on micro elastic theory. In the proposed ferroelasticity model, the information of deformation, which is calculated by the mechanical simulation, is introduced to the elastic energy term of phase-field equation. The mechanical properties change in accordance with the phase transformation. By coupling the deformation and phase transformation, the mechanical behavior of ferroelasticity is analyzed. On the basis of the developed model, a simple simulation is conducted.
結晶塑性モデルによるDP鋼の成形限界特性評価 (特集材料科学におけるシミュレーション技術の活用)

寺田賢二郎, 村松眞由

金属　85　(11)　908-914　2015/11
Publisher: アグネ技術センター
ISSN： 0368-6337
275 Finite strain inelastic constitutive model for thermoplastic resin and coupled analysis with heat conduction

Matsubara Seishiro, Terada Kenjiro

The Computational Mechanics Conference　2015　(28)　"275-1"-"275-3"　2015/10/10
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
251 Prediction of Drying Deformation of Potteries by using Finite Element Method

Saitou Toshiyuki, Shin Hiroto, Katsuda Yasuhiro, Umeda Manabu, Oide Kai, Mihara Yasuko, Terada Kenjiro, Matsubara Seshiro

The Computational Mechanics Conference　2015　(28)　"251-1"-"251-2"　2015/10/10
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
相変態を考慮した結晶塑性FEシミュレーションによる局所応力評価

堤成一郎, FINCATO Riccardo, 寺田賢二郎

材料とプロセス(CD-ROM)　28　(2)　ROMBUNNO.201　2015/09/01

ISSN： 1882-8922
地震荷重を受ける鋼製橋脚のき裂進展評価

番場良平, 新宅勇一, 村松眞由, 高瀬慎介, 森口周二, 寺田賢二郎, 堤成一郎

計算工学講演会論文集(CD-ROM)　20　ROMBUNNO.A-1-2　2015/06/08
Publisher: 日本計算工学会
ISSN： 1342-145X
有限被覆法による自動き裂進展解析

新宅勇一, 新宅勇一, 村松眞由, 高瀬慎介, 森口周二, 寺田賢二郎, 堤成一郎, 車谷麻緒

計算工学講演会論文集(CD-ROM)　20　ROMBUNNO.B-8-3　2015/06/08

ISSN： 1342-145X
埋込型結合力モデルを導入した損傷構成則

新宅勇一, 新宅勇一, 村松眞由, 高瀬慎介, 森口周二, 寺田賢二郎, 堤成一郎

計算工学講演会論文集(CD-ROM)　20　ROMBUNNO.D-4-2　2015/06/08
Publisher: 日本計算工学会
ISSN： 1342-145X
Damage analysis of quasi-brittle materials in consideration of geometrical nonlinearity

20　4p　2015/06
Publisher: 日本計算工学会
Development of a Numerical Method for Debris Flow based on Stabilized Finite Element Method

20　4p　2015/06
Publisher: 日本計算工学会
Design Optimization for Cross Section of Composite Plate

20　4p　2015/06
Publisher: 日本計算工学会
Multiscale Numerical Experiment for Evaluating Tsunami Damping Effects of Coastal Forest

20　4p　2015/06
Publisher: 日本計算工学会
A simulation of a drop-experiment of crushed stone using DEM

森口周二, 橘一光, 寺田賢二郎

計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science　20　5p　2015/06
Publisher: 日本計算工学会
Modeling of deformation characteristic of layered rocks using homogenization method

Kyoya Takashi, Terada Kenjiro

Annual report of the Society for the Promotion of Construction Engineering　50　3-10　2015/04/01
Publisher: Tohoku University
ISSN： 0288-9994
残留オーステナイトのTRIP効果が局所応力分布に与える影響に関する結晶塑性FE解析

堤成一郎, FINCATO Riccardo, 寺田賢二郎

溶接学会全国大会講演概要　(96)　124-125　2015/03/20
MULTI-SCALE CHARACTERIZATION OF TENSILE AND COMPRESSIVE STRENGTHS OF HETEROGENEOUS ROCK MASS

43　244-247　2015/01/08
Publisher: [土木学会岩盤力学委員会]
ISSN： 1880-7623
双晶を考慮した六方晶の結晶塑性モデルによるMgY合金成形限界解析

村松眞由, 寺田賢二郎, 安藤大輔, 小池淳一

日本金属学会講演概要(CD-ROM)　157th　2015

ISSN： 2433-3093
Mechanically Induced Martensitic Transformation of Retained Austenite Analysed by Crystal Plasticity FE Analysis

Tsutsumi Seiichiro, Fincato Riccardo, Terada Kenjiro

Preprints of the National Meeting of JWS　2015　(0)　124-125　2015
Publisher: JAPAN WELDING SOCIETY

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本研究では、熱力学モデルを基に、有限変形理論の枠組みで定式化された単結晶の結晶塑性モデルに考慮するマルテンサイト変態モデルを応力誘起変態に特化した形に修正し、精度の高い三次元変形解析を可能にすることを目的とする。また、単調載荷条件下の変形解析を行い、マルテンサイト変態が材料の応力ひずみ曲線や局所的な応力状態に与える影響を明らかにする。
A study on a shape effect in rockfall simulation using DEM

S. Moriguchi, I. Tachibana, K. Terada, S. Takase, T. Kyoya, J. Kato, S. Sawada, A. Yashima

Geomechanics from Micro to Macro, Vols I and II　1　213-218　2015
A Simulation Coupling Electrochemical and Mechanical Behaviors of Porous Electrodes in Solid Oxide Fuel Cell Subject to Start-stop Operation

MURAMATSU Mayu, TAKAHASHI Ken, TAKASE Shinsuke, KAWADA Tatsuya, TERADA Kenjiro

The Computational Mechanics Conference　2014　(27)　418-419　2014/11/22
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
Preliminary Study of Multi-scale Topology Optimization Using Phase-Field Method

Kato Junji, Kamo Yoshiki, Takaki Tomohiro, Terada Kenjiro, Kyoya Takashi

The Computational Mechanics Conference　2014　(27)　587-588　2014/11/22
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
塑性変形に伴う損傷を考慮した結合力モデルの提案

新宅勇一, 村松眞由, 堤成一郎, 寺田賢二郎, 京谷孝史, 加藤準治, 森口周二, 高瀬慎介

日本機械学会計算力学講演会論文集(CD-ROM)　27th　(0)　ROMBUNNO.1913-496　2014/11/21
Publisher: 一般社団法人日本機械学会
ISSN： 1348-026X
多結晶体内の水素拡散および水素脆化き裂進展連成解析

新宅勇一, 村松眞由, 堤成一郎, 寺田賢二郎, 京谷孝史, 加藤準治, 森口周二, 高瀬慎介

日本機械学会計算力学講演会論文集(CD-ROM)　27th　(0)　ROMBUNNO.2020-542　2014/11/21
Publisher: 一般社団法人日本機械学会
ISSN： 1348-026X
マイクロポーラ弾性体を対象としたマルチスケール解析 Invited

佐藤綾美, 山田崇恭, 泉井一浩, 西脇眞二, 寺田賢二郎

2014年度年次大会，日本機械学会，東京，日本，J0110201　2014/09
残留オーステナイトの加工誘起マルテンサイト変態に関する結晶塑性FE解析

堤成一郎, FINCATO Riccardo, 寺田賢二郎, 石田智広

溶接学会全国大会講演概要　2014　(95)　332-333　2014/08/15
Publisher: 一般社団法人溶接学会
DOI： 10.14920/jwstaikai.2014f.0_332 　

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TRIP効果を積極活用することにより、破壊や疲労き裂の発生時期や進展速度などが変化することが確認されている。本研究では、マルテンサイト変態を考慮した単結晶の構成モデルを有限変形理論の枠組みで定式化し、それを実装した三次元有限要素ツールにより変形解析を行うことで、破壊起点に対する組織因子の影響をミクロの視点から調査することを目的とする。
安定化有限要素法を用いた津波遡上の2D‐3Dハイブリッド計算

高瀬慎介, 加藤準治, 森口周二, 寺田賢二郎, 京谷孝史, 野島和也, 桜庭雅明, 車谷麻緒, 浅井光輝, 樫山和男

計算工学講演会論文集(CD-ROM)　19　ROMBUNNO.G-7-6　2014/06/11

ISSN： 1342-145X
化学的作用を考慮した多結晶体内のき裂進展解析

新宅勇一, 寺田賢二郎, 加藤準治, 京谷孝史, 森口周二, 高瀬慎介, 堤成一郎

計算工学講演会論文集(CD-ROM)　19　ROMBUNNO.D-6-4　2014/06/11

ISSN： 1342-145X
Topology Optimization for Composites Considering Elastoplasticity and Its Analytical Sensitivity

19　6p　2014/06
Publisher: 日本計算工学会
Multiscale analysis scheme for injection molded parts taking into account fiber length distribution

19　4p　2014/06
Publisher: 日本計算工学会
A Modeling Error in Behavior Prediction of Rockfalls Using Sphere Elements Based DEM

森口周二, 橘一光, 寺田賢二郎

計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science　19　6p　2014/06
Publisher: 日本計算工学会
Homogenization Method for Micropolar Elastic Bodies Invited

19　6p　2014/06
Publisher: 日本計算工学会
残留オーステナイトのTRIP効果が局所応力に与える影響に関する結晶FE解析

堤成一郎, FINCATO Riccardo, 寺田賢二郎, 石田智広

溶接学会全国大会講演概要　2014　(94)　228-229　2014/03/20
Publisher: 一般社団法人溶接学会

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残留オーステナイトなどを含む鉄鋼材料の強度-延性バランスは、加工誘起マルテンサイト変態（TRIP）効果により変化する。本研究では、マルテンサイト変態を考慮した結晶モデルを導入した有限要素解析を行い、局所的な応力分布に対するTRIPの影響について考察を行う。
結晶塑性FEMとMulti Phase Field法を用いたMgY合金の連成解析

寺田賢二郎, 石田智広, 安藤大輔, 小池淳一

日本金属学会講演概要(CD-ROM)　154th　2014

ISSN： 2433-3093
Development of a system for distributing urgent evacuating information during Tsunami

大保直人, 大保直人, 今村文彦, 寺田賢二郎, 有賀義明, 堀宗朗, 山内芳朗, 高田史俊, 稲垣幸子

東濃地震科学研究所報告　(33)　2014
2912 ON CONVERGENCE RATE OF CUTTING-PLANE ALGORITHM IN NUMERICALANALYSES OF A CYCLIC PLASTICITY MODEL

Fincato Riccardo, Tsutsumi Senchiro, Terada Kenjiro

The Computational Mechanics Conference　2013　(26)　"2912-1"-"2912-3"　2013/11/02
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X

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The recourse to numerical techniques in plasticity has become a crucial point to speed up computational time The nonlinear behavior of material forces the use of a small step size in order to keep the accuracy of the solution and the stability of the algorithm Return Mapping technique [1], here adapted to the Subloading Surface model [2], guarantees a quadratic convergence rate on the correct solution even in a large step analysis, justifying its use especially where a large number of iterations is required (cyclic plasticity problems, etc) and reducing the computing effort
2514 A multi-scale analysis method for electro-chemo-mechanical behavior involving sintering of porous micro structure

TERADA Kenjiro, TAKASE Shinsuke, TAKAHASHI Ken, WATANABE Satoshi, KAWADA Tatsuya

The Computational Mechanics Conference　2013　(26)　"2514-1"-"2514-2"　2013/11/02
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X

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The present study addresses a multi-scale analysis method for electro-chemo-mechanical coupling behavior involving sintering of porous micro structure Physical problems to be considered are the time evolutions of (a) sintering of porous micro structure, (b) electro-chemical potentials, (c) in addition to (c) inelastic deformation processes with thermal and reductive expansions The corresponding macro-scale models are derived based on the homogenization method considering the time evolutions of sintering The numerical examples show how the sintering of microstructure effects performance degradation of anode-supported flat-tube cell
1903 Material Design using Multiscale Topology Optimization

Kato Junji, Yachi Daishun, Takase Shinsuke, Terada Kenjiro, Kyoya Takashi

The Computational Mechanics Conference　2013　(26)　"1903-1"-"1903-2"　2013/11/02
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
多結晶塑性挙動を考慮したマルチ・スケールき裂進展解析

新宅勇一, 寺田賢二郎, 堤成一郎, 菊池正紀

日本機械学会計算力学講演会論文集(CD-ROM)　26th　ROMBUNNO.2304　2013/11/01
Application of High Performance Element to Improve the Numerical Stability of Multiscale Problems with Large Deformation

18　4p　2013/06
Publisher: 日本計算工学会
A multi-scale analysis method for electrochemo-mechanicalcoupling behavior involving sintering of porous micro structure of solid oxide fuel cells

18　4p　2013/06
Publisher: 日本計算工学会
Topology optimization for composites considering material nonlinearity

18　4p　2013/06
Publisher: 日本計算工学会
Estimation of Fluid Body Force Around Object using Finite Cover Method

18　4p　2013/06
Publisher: 日本計算工学会
Crack Growth Analysis in Composite Material Using S-version FEM

18　4p　2013/06
Publisher: 日本計算工学会
Deformation and Strength Characterization of Mg Alloys with Rolled Crystallographic Textures by Crystal Plasticity Finite Element Method

石田智広, 渋谷慎兵, 加藤準治, 寺田賢二郎, 京谷孝史, 安藤大輔, 小池淳一

日本機械学会論文集 A編(Web)　79　(808)　2013

ISSN： 1884-8338
OS0317 Deformation twinning model of HCP metals and its application to finite crystal plasticity FEM

ISHIDA Tomohiro, SHIBUTANI Shinpei, KATO Junji, TERADA Kenjiro, KYOYA Takashi, ANDO Daisuke, KOIKE Junichi

2012　"OS0317-1"-"OS0317-3"　2012/09/22
Publisher: The Japan Society of Mechanical Engineers

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A thermodynamics-based constitutive model, which accounts for both crystallographic slip and deformation twinning, is developed for a single crystal of hcp metals within the framework of finite crystal plasticity. While the volume fractions of stress-free twin deformations are introduced as internal variables, the free-energy involves the bulk energy of separate phases and the surface energy at twin interfaces, which are introduced as functions of the internal variables, in addition to the standard hardening-related energy in crystal plasticity framework. After the formulation is described in detail, a series of numerical examples is presented to verify the performance of the proposed model in predicting the deformation twinning, the successive deformation process and the twinning-induced stress responses. The results are studied with reference to the theoretical consequences and the experimental results reported in the literature.
OS0316 The relationships between the amounts of localized deformation and deformation twin type

ANDO Daisuke, SUTOU Yuji, KOIKE Junichi, ISHIDA Tomohiro, SIBUTANI Sinpei, KATO Jungi, TERADA Kenzirou, KYOYA Takashi

2012　"OS0316-1"-"OS0316-3"　2012/09/22
Publisher: The Japan Society of Mechanical Engineers

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In this study, the origin of amounts of localized strain in basal textured Magnesium alloy sheets was investigated. First, grid patterns were drawn on a top surface of sample by Focus Ion Beam system. And then, a distribution of crystal orientation from same area was observed by SEM/EBSD. From these methods, the relationship between the localized strain and crystal orientation was revealed. In generally, the amounts of strains are dependent on the crystal orientation, which means the facility of slip deformation. However, my results show that localized strain is dependent on the existence or absence of twins and twin types, and but not on the Schmid factor of basal slip. And I suggest that {1012} type has the roll of strain accommodation to satisfy the strain compatibility with neighbor grain in primary deformation stage and continue to cancel the strain of slip during deformation. So the grain with {10-12} type slightly deformed. On the other hand, {10-11} type has the roll of accommodation strain component to conform to externally applied stress. But {10-11} twin easily generate double twin. And the grain with double twin localized severely deformed and formed surface steps or cracks.
Prediction of sound absorption coefficient by a multi-scale analysis for poro-elastic media Peer-reviewed

YAMAMOTO Takashi, TERADA Kenjiro, NISHIWAKI Shinji

The Journal of the Acoustical Society of Japan　68　(9)　480-485　2012/09/01
Publisher: The Acoustical Society of Japan (ASJ)
DOI： 10.20697/jasj.68.9_480 　

ISSN： 0369-4232
Topology Optimization of Microstructures Applying a Decoupling Multi-scale Analysis

17　4p　2012/05
Publisher: 日本計算工学会
Anisotropic elastoplastic-creep-damage model and its parameter identification

17　4p　2012/05
Publisher: 日本計算工学会
Application of particle filter for integrity assessment of tunnel lining

17　4p　2012/05
Publisher: 日本計算工学会
Recent Trends of Computational Engineering (Part II)

17　(1)　2700-2709　2012/01/31
Publisher: 日本計算工学会
ISSN： 1341-7622
結晶塑性FEMによるマグネシウム合金の強度発現機構の解明

石田智広, 渋谷慎兵, 加藤準治, 寺田賢二郎, 京谷孝史, 安藤大輔, 小池淳一

計算工学講演会論文集(CD-ROM)　17　2012

ISSN： 1342-145X
緊急津波避難情報システムの開発

大保直人, 大保直人, 今村文彦, 寺田賢二郎, 有賀義明, 堀宗朗, 山内芳朗, 高田史俊, 稲垣幸子

地域安全学会梗概集　(31)　2012
Estimation of macroscopic material properties using sintering simulation of porous microstructure affected by mechanical effects

Takashi Sasagawa, Ken Takahashi, Kenjiro Terada, Tatsuya Kawada

Transactions of the Japan Society for Computational Engineering and Science　2012　4　2012/01/01
Round-Table Talk by Authorized Researchers, "Recent Trends of Computational Engineering (Part 1)"

16　(4)　2651-2661　2011/10/31
Publisher: 日本計算工学会
ISSN： 1341-7622
Maximization of Energy Absorption Capacity for Fiber Reinforced Composites Considering Damage

16　4p　2011/05
Publisher: 日本計算工学会
ANISOTROPIC VISCOELASTIC CONSTITUTIVE LAW IMPLEMENTED IN GENERAL CAE TOOL

16　4p　2011/05
Publisher: 日本計算工学会
Prediction of macroscopic material properties affected by creep deformation and temporal changes by sintering of porous micro structure

16　4p　2011/05
Publisher: 日本計算工学会
有限被覆法を用いたレベルセット法に基づく設計依存荷重問題に対するトポロジー最適化 Invited

真鍋匡利, 山田崇恭, 泉井一浩, 西脇眞二, 車谷麻緒, 寺田賢二郎

計算工学講演会論文集Vol.16，日本計算工学会，柏，日本，No.D-7-3　2011/05
106 Topology optimization for compliant mechanisms using finite cover method incorporating level set boundary expressions

MANABE Masatoshi, YAMADA Takayuki, IZUI Kazuhiro, NISHIWAKI Shinji, KURUMATANI Mao, TERADA Kenjiro

2010　(9)　"106-1"-"106-4"　2010/12/09
Publisher: The Japan Society of Mechanical Engineers

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In this paper, first, a topology optimization problem is formulated based on the level set method and a method for regularizing the optimization problem by the Tikhonov regularization method is explained. The reaction-diffusion equation that updates the level set function is then derived and an optimization algorithm, which uses the finite element method to solve the equilibrium equations and the reaction-diffusion equation when updating the level set function, is constructed. Next, the implementation of combining the level set-based topology optimization and the finite cover method is explained. Finally, a numerical examples is provided to demonstrate the effectiveness of the proposed method of topology optimization for compliant mechanisms.
A Homogenization-Based Prediction Method of Macroscopic Yield Strength of Polycrystalline Metals Subjected to Cold-Working

Kenjiro Terada, Ikumu Watanabe, Masayoshi Akiyama, Shigemitsu Kimura, Kouichi Kuroda

Advanced Computational Materials Modeling: From Classical to Multiâ-Scale Techniques　379-412　2010/11/08
Publisher: Wiley-VCH
DOI： 10.1002/9783527632312.ch10 　
2102 Topological optimum design using finite cover method incorporating level set boundary expressions

MANABE Masatoshi, YAMADA Takayuki, IZUI Kazuhiro, NISHIWAKI Shinji, KURUMATANI Mao, TERADA Kenjiro

2010　(20)　"2102-1"-"2102-3"　2010/10/27
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-0286

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In this paper, first, a topology optimization problem is formulated based on the level set method and a method for regularizing the optimization problem by the Tikhonov regularization method is explained. The reaction-diffusion equation that updates the level set function is then derived and an optimization algorithm, which uses the finite element method to solve the equilibrium equations and the reaction-diffusion equation when updating the level set function, is constructed. Next, the implementation of combining the level set-based topology optimization and the finite cover method is explained. Finally, a numerical examples is provided to demonstrate the effectiveness of the proposed method of topology optimization for minimum mean compliance problems.
3101 A design method for micro-structure of poroelastic sound-absorbing media by the homogenization method

YAMAMOTO Takashi, MARUYAMA Shinichi, TERADA Kenjiro, IZUI Kazuhiro, NISHIWAKI Shinji

2010　(20)　"3101-1"-"3101-6"　2010/10/27
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-0286

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In this paper we propose a model for sound-absorbing poroelastic materials using the homogenization method, based on the asymptotic approach. The proposed model is consistent with microscopic structure and yields a macroscopic governing equation with properties predicted directly from microscopic geometry. In this model, four properties for the solid phase and two properties for the fluid phase are calculated by averaging characteristic functions of the periodic microscale model. These properties are then substituted into the macroscopic governing equations to evaluate performance such as the sound absorption coefficient for normal incidence. We show how the actual size of the microscale affects the sound absorption coefficient, using a three-dimensional microstructure model.
029 Topology Optimization for Linear Elastic Materials Using Finite Cover Method Incorporating Level Set Boundary Expressions

MANABE Masatoshi, YAMADA Takayuki, IZUI Kazuhiro, NISHIWAKI Shinji, KURUMATANI Mao, TERADA Kenjiro

2010　566-568　2010/10/09
Publisher: The Japan Society of Mechanical Engineers

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In this paper, first, a topology optimization problem is fomiulated based on the level set method and a method for regularizing the optimization problem by the Tikhonov regularization method is explained. The reaction-diffusion equation that updates the level set function is then derived and an optimization algorithm, which uses the finite element method to solve the equilibrium equations and the reaction-diffusion equation when updating the level set function, is constructed. Next, the implementation of combining the level set-based topology optimization and the finite cover method is explained. Finally, a numerical examples is provided to demonstrate the effectiveness of the proposed method of topology optimization for minimum mean compliance problem of linear elastic materials.
レベルセット法による形状表現に基づく有限被覆法を用いた構造形態の創生 Invited

真鍋匡利, 山田崇恭, 泉井一浩, 西脇眞二, 車谷麻緒, 寺田賢二郎

コロキウム構造形態の解析と創生2010，日本建築学会，東京，日本　17-22　2010/10
815 Topology optimization for maximum stiffness problems using finite cover method incorporating level set boundary expressions

MANABE Masatoshi, YAMADA Takayuki, IZUI Kazuhiro, NISHIWAKI Shinji, KURUMATANI Mao, TERADA Kenjiro

The Computational Mechanics Conference　2010　(23)　391-392　2010/09/23
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
カルサイト双晶応力計の従来の問題点と人工カルサイトによる力学試験

坂口有人, 阪口秀, 西浦泰介, 柳澤和道, 久田真, 皆川浩, 寺田賢二郎, 京谷孝史

日本地質学会学術大会講演要旨　117th　101　2010/09/15

DOI： 10.14863/geosocabst.2010.0.196.0 　

ISSN： 1348-3935
J1202-1-2 Level set-based structural topology optimization using finite cover method

MANABE Masatoshi, YAMADA Takayuki, IZUI Kazuhiro, NISHIWAKI Shinji, KURUMATANI Mao, TERADA Kenjiro

The proceedings of the JSME annual meeting　2010　(7)　295-296　2010/09/04
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.2010.7.0_295 　
803 Multi-scale thermo-elastic analysis of porous media in consideration of micro-scale heat transfer

KURUMATANI Mao, TERADA Kenjiro

2010　(18)　215-216　2010/08/27
Publisher: The Japan Society of Mechanical Engineers

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This paper presents a multi-scale analysis method for thermo-elastic coupled problems of porous media based on the homogenization method, which accounts for the effects of the size of periodic microstructures or unit cells. The size/scale effect under consideration is supposed to be caused by the amount of microscopic heat transfer. The macroscopic heat conduction phenomena are simulated with variously-sized unit cell models to demonstrate the potential of the proposed method in comparison with the corresponding single-scale direct analyses.
Matching Between CAE and Computational Engineering

TERADA Kenjiro

15　(3)　2345-2345　2010/07/31

ISSN： 1341-7622
MICRO-MACRO NON-COUPLING ANALYSIS METHOD FOR PARTIALLY IMPROVED GROUNDS BY USING MULTI-SCALE ANALYSIS

15　(2)　945-948　2010/05
Publisher: 日本計算工学会
ISSN： 1342-145X
A Fluid-Structure Interaction Analysis based on the Finite Cover Method

15　(2)　807-810　2010/05
Publisher: 日本計算工学会
ISSN： 1342-145X
PARAMETER IDENTIFICATION OF MATERIALS FOR ANISOTROPIC ELASTOPLASTIC FORMULATION

15　(2)　813-816　2010/05
Publisher: 日本計算工学会
ISSN： 1342-145X
A numerical multiscale analysis method for mechanical deterioration due to redox reaction-induced expansion/contraction

15　(2)　997-1000　2010/05
Publisher: 日本計算工学会
ISSN： 1342-145X
Parameter identification for rate-dependent constitutive models of resin materials

15　(2)　667-670　2010/05
Publisher: 日本計算工学会
ISSN： 1342-145X
有限被覆法を用いたレベルセット法に基づくトポロジー最適化 Invited

真鍋匡利, 山田崇恭, 泉井一浩, 西脇眞二, 車谷麻緒, 寺田賢二郎

計算工学講演会論文集第15巻第2号，日本計算工学会，福岡，日本　15　(2)　1089-1092　2010/05
17. エンジニア向け理論教育 CAEユニバーシティ力学系講座が目指すもの

Kenjiro Terada, Norio Hirayama

CYBERNET NEWS　(131)　22-23　2010
Publisher: サイバネットシステム
非線形CAEの研究動向と材料モデリング

寺田賢二郎

Mech D&A News　2010　(1)　1-7　2010
Publisher: Mechanical Design & Analysis Co.
1404 Dynamic fracture simulation of concrete in tension under high strain rate

KURUMATANI Mao, TERADA Kenjiro, OKAZAWA Shigenobu, KASHIYAMA Kazuo

The Computational Mechanics Conference　2009　(22)　155-156　2009/10/10
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
Strength evaluation of ultra high-strength cement paste by crack propagation analysis of microstructure

Proceedings of the conference on computational engineering and science　14　(2)　945-948　2009/05
Publisher: 日本計算工学会
ISSN： 1342-145X
Microscopic and macroscopic size/scale effect behavior in quasi-brittle materials

Proceedings of the conference on computational engineering and science　14　(2)　973-976　2009/05
Publisher: 日本計算工学会
ISSN： 1342-145X
Characterization of forming limit of dual phase steels using a crystal plasticity model

Proceedings of the conference on computational engineering and science　14　(2)　963-966　2009/05
Publisher: 日本計算工学会
ISSN： 1342-145X
Multi-scale thermo-elastic coupled analysis of porous media in consideration of micro-scale heat transfer

Proceedings of the conference on computational engineering and science　14　(2)　977-980　2009/05
Publisher: 日本計算工学会
ISSN： 1342-145X
Numerical experiment for anisotropic viscoelastic behavior of fibre reinforced composite materials

Proceedings of the conference on computational engineering and science　14　(2)　1051-1054　2009/05
Publisher: 日本計算工学会
ISSN： 1342-145X
Multi-scale analysis for partialy improved ground by using non-linear elastic constitutive model and its experimental verification

Proceedings of the conference on computational engineering and science　14　(1)　445-448　2009/05
Publisher: 日本計算工学会
ISSN： 1342-145X
数値材料試験による異方性非線形材料特性の算出～その2：繊維強化プラスチックのマルチスケール解析～

Kenjiro Terada, Norio Hirayama

CAEのあるものづくり　11　10-13　2009
Publisher: サイバネットシステム
723 A study of discrete crack growth analysis for quasi-brittle materials

KURUMATANI Mao, TERADA Kenjiro

The Computational Mechanics Conference　2008　(21)　580-581　2008/11/01
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
有限被覆法を用いたレベルセット法に基づく構造最適化 Invited

山田恭崇, 山崎慎太郎, 西脇眞二, 泉井一浩, 吉村允孝, 車谷麻緒, 寺田賢二郎

第18設計工学・システム部門講演会，日本機械学会，，京都，日本，No. 3106　2008/10
マルチスケールモデリングによる多結晶金属のミクロ塑性ひずみの評価

渡邊育夢, 寺田賢二郎, 堤成一郎

土木学会年次学術講演会講演概要集(CD-ROM)　63rd　(Disk 2)　ROMBUNNO.CS08-07　2008/08/13
Eulerian Dynamic Large Deformation Solid Analysis by Finite Cover Method

TERASAWA Hideyuki, KURUMATANI Mao, TERADA Kenjiro, OKAZAWA Shigenobu, KASHIYAMA Kazuo

Proceedings of the conference on computational engineering and science　13　(2)　785-788　2008/05/19
Publisher: 日本計算工学会
ISSN： 1342-145X
A METHOD FOR CRACK PROPAGATION ANALYSIS USING NODAL-INTEGRATION FEM AND ITS APPLICATION

KURUMATANI Mao, TERADA Kenjiro, KYOYA Takashi

Proceedings of the conference on computational engineering and science　13　(1)　273-276　2008/05/19
Publisher: 日本計算工学会
ISSN： 1342-145X
DEVELOPMENT OF A METHOD FOR DYNAMIC CRACK PROPAGATION ANALYSIS USING COHESIVE CRACK MODEL

IWATA Satoshi, KURUMATANI Mao, TERADA Kenjiro, OKAZAWA Shigenobu, KASHIYAMA Kazuo

Proceedings of the conference on computational engineering and science　13　(1)　281-284　2008/05/19
Publisher: 日本計算工学会
ISSN： 1342-145X
NONLINEAR ANALYSES OF SOLIDS UTILIZING STRESS CONTINUITY BASED ON THE NODAL-INTEGRATION FEM

KURUMATANI Mao, TERADA Kenjiro

13　(1)　39-40　2008/05/19

ISSN： 1342-145X
Multiscale CAE system for electromagnetic problems

YAMAMOTO Koji, ISHIDA Tomohiro, HIRAYAMA Norio, TERADA Kenjiro

Proceedings of the conference on computational engineering and science　13　(1)　383-386　2008/05/19
Publisher: 日本計算工学会
ISSN： 1342-145X
DEVEROPMENT OF MULTISCALE CAE SYSTEM FOR ANISOTROPIC HYPERELASTIC MATERIALS

INUGAI Takenori, TERADA Kenjiro, HIRAYAMA Norio

Proceedings of the conference on computational engineering and science　13　(1)　379-382　2008/05/19
Publisher: 日本計算工学会
ISSN： 1342-145X
MULTISCALE ANALYSIS OF REINFORCED GROUND USING NON-LINEAR ELASTIC CONSTITUTION OF SOIL REGULATING 3-DIMESIONAL PRINCIPLE DIRECTION

ISHIKAWA Akira, TERADA Kenjiro

Proceedings of the conference on computational engineering and science　13　(1)　353-356　2008/05/19
Publisher: 日本計算工学会
ISSN： 1342-145X
Level-set-based solid modeling for heterogeneous microstructure and its application to multiscae analysis

USHIDA Takashi, KURUMATANI Mao, TERADA Kenjiro, KYOYA Takashi

Proceedings of the conference on computational engineering and science　13　(1)　327-330　2008/05/19
Publisher: 日本計算工学会
ISSN： 1342-145X
Strength prediction of cold-worked steel tubes by the crystal plasticity homogenizing method

TERADA Kenjiro, NATORI Misaki, WATANABE Ikumu, KIMURA Shigemitsu, KURODA Kouichi, AKIYAMA Masayoshi

Proceedings of the conference on computational engineering and science　13　(1)　331-334　2008/05/19
Publisher: 日本計算工学会
ISSN： 1342-145X
数値材料試験による異方性非線形材料特性の算出～数値材料試験用入力データの計測手順とデータ解析～

Norio Hirayama, Kenjiro Terada

CAEのあるものづくり　10-12　2008/02
Publisher: サイバネットシステム
Numerical material testing for strength evaluation of polycrystalline metals

Kenjiro Terada, Ikumu Watanabe

Proceedings of 4th International Conference on Multiscale Materials Modeling, MMM 2008　168-173　2008/01/01
ボクセル有限要素法による鋼構造物の三次元超音波探傷シミュレーション

山田真幸, 平本邦幸, 生出佳, 寺田賢二郎

鋼構造論文集　15　(59)　57-64　2008

DOI： 10.11273/jssc1994.15.59_57 　
鉄鋼材料の微視的非均質性と巨視的機械的性質の相互関係－均質化法に基づく数値材料実験－

寺田賢二郎

塑性と加工（日本塑性加工学会誌）　39　(564)　13-18　2008/01
Publisher: （日本塑性加工学会誌
DOI： 10.9773/sosei.49.13 　

ISSN： 0038-1586
Characterization of macroscopic yield strength of polycrystalline metals by multiscale metal forming analysis

Kenjiro Terada, Hirohito Tabata, Ikumu Watanabe, Masayoshi Akiyama

Computational Plasticity - Fundamentals and Applications, COMPLAS IX　(PART 1)　350-353　2007/12/01
レベルセット法に基づく構造最適化における有限被覆法の適用 Invited

池内駿介, 山崎慎太郎, 西脇眞二, 泉井一浩, 吉村允孝, 車谷麻緒, 寺田賢二郎

第19回計算力学講演会，日本機械学会，京都，日本　679-680　2007/11
複合材料の数値材料実験のススメその３～数値材料実験の理論と実際：伝熱と浸透流編～

Kenjiro Terada

強化プラスチックス　53　(6)　277-286　2007/06
Publisher: 強化プラスチック協会
ISSN： 0452-9685
Development of multiscale analysis method utilizing model of crack propagations

Proceedings of the conference on computational engineering and science　12　(2)　519-522　2007/05
Publisher: 日本計算工学会
ISSN： 1342-145X
Elastic-plastic analysis of heterogeneous materials and structures by the nodal-integration finite element method

Proceedings of the conference on computational engineering and science　12　(1)　283-286　2007/05
Publisher: 日本計算工学会
ISSN： 1342-145X
Approximation properties of nodal-integration finite element method

Proceedings of the conference on computational engineering and science　12　(1)　35-38　2007/05
Publisher: 日本計算工学会
ISSN： 1342-145X
Finite cover method for multiple crack growth in 3-D structural members

Proceedings of the conference on computational engineering and science　12　(1)　115-118　2007/05
Publisher: 日本計算工学会
ISSN： 1342-145X
Development of multiscale simulation systems

Proceedings of the conference on computational engineering and science　12　(1)　151-154　2007/05
Publisher: 日本計算工学会
ISSN： 1342-145X
Characterization of yielding behavior of polycrystalline metals by multiscale metal forming analyses

寺田賢二郎, 田端大人, 渡邊育夢, 秋山雅義, 堤成一郎

Proceedings of the conference on computational engineering and science　12　(1)　321-324　2007/05
Publisher: 日本計算工学会
ISSN： 1342-145X
複合材料の数値材料実験のススメその２～数値材料実験の理論と実際：伝熱と浸透流編～

Kenjiro Terada

強化プラスチックス　53　(5)　246-253　2007/05
Publisher: 強化プラスチック協会
ISSN： 0452-9685
複合材料の数値材料実験のススメその１～等価物性と均質化法～

Kenjiro Terada

強化プラスチックス　53　(4)　205-210　2007/04
Publisher: 強化プラスチック協会
ISSN： 0452-9685
マルチスケールCAE ～数値材料試験のススメ～

寺田賢二郎

CAEのあるものづくり　5　9-11　2006/09
Publisher: サイバネットシステム
Round-Table Talk by Authorized Researchers, 'Computational Engineering from Now on'

Journal of the Japan Society for Computational Engineering and Science　11　(1)　1304-1314　2006/02/28
Publisher: 日本計算工学会
ISSN： 1341-7622
Two-scale analysis of polycrystalline metals with decoupled micro-macro analysis method

Watanabe Ikumu, Terada Kenjiro

NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan　55　(0)　153-153　2006
Publisher: National Committee for IUTAM
DOI： 10.11345/japannctam.55.0.153.0 　

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We propose a new procedure for approximately solving two-scale boundary value problems (BVPs) that can be derived in the framework of mathematical homogenization method for nonlinear heterogeneous solids. Although the micro- and the macroscopic BVPs are strongly coupled in the original algorithm for nonlinear two-scale BVPs, the proposed method enables us to decouple them without losing the distinct features of the two-scale BVP. That is, in this method, the solution for the macroscopic problem still reflects the mechanical behavior characterized for the microscopic one, and vise versa. We carry out representative numerical analyses for the structure with polycrystalline metal to demonstrate the capability and availability of the proposed method.
機械式レゾネータ設計のためのトポロジー最適化 Invited

西脇眞二, 前田泰典, 泉井一浩, 吉村允孝, 松井和巳, 寺田賢二郎

第55回理論応用力学講演会，，京都，日本　129-130　2006/01

DOI： 10.11345/japannctam.55.0.50.0 　
1005 A homogenization method for heat conduction analysis of porous medium

KURUMATANI Mao, TERADA Kenjiro

The Computational Mechanics Conference　2005　(18)　357-358　2005/11/17
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
906 Application of the discontinuous Galerkin approximation to the finite cover method

KURUMATANI Mao, TERADA Kenjiro

The Computational Mechanics Conference　2005　(18)　375-376　2005/11/17
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
1217 Numerical estimation of the mechanical properties of carbon steel and its microstructures by using the phase-field and homogenization method

Matsui Kazumi, Koyama Toshiyuki, Terada Kenjiro

The Computational Mechanics Conference　2005　(18)　279-280　2005/11/17
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
均質化法とその工学的応用 -ミクロとマクロのCAEツールとして-

寺田賢二郎

Journal of the Japan Society of Mechanical Engineers　108　(1043)　802-804　2005/10/05
Publisher: Japan Society for Computational Engineering and Sciences
ISSN： 0021-4728
414 Development of Computational Method for Crack Growth in Rock

ISHII Tateki, KYOYA Takashi, TERADA Kenjiro, KISHINO Yuji

54　125-126　2005
Publisher: 日本材料学会
A numerical study on the grain size effect in multi-scale modeling

Watanabe Ikumu, Terada Kenjiro, Akiyama Masayoshi

NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan　54　(0)　132-132　2005
Publisher: National Committee for IUTAM
DOI： 10.11345/japannctam.54.0.132.0 　

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This study explores the effect of grain size on the macroscopic material behavior of polycrystalline metals in the framework of multi-scal modeling, based on the homogenization theory. Our computational study is intended to reproduce the so-called Hall-Petch relationship for the macroscopic strength by introducing two types of hypothesis for the plastic material behavior of single crystals; one is the applicability of the Hall-Petch relationship to each crystal and the other is that of strain gradient theory for hardening characteristics.
W01-(2) 均質化法に基づく多結晶塑性モデリング : マクロ変形強度特性に対する加工履歴の影響評価の試み(マルチスケール多結晶塑性モデリングの考え方,ワークショップ)

寺田賢二郎, 渡邊育夢, 田端大人, 秋山雅義

年次大会講演資料集　2005　(0)　257-258　2005
Publisher: 一般社団法人日本機械学会
DOI： 10.1299/jsmemecjsm.2005.8.0_257 　
1216 Prediction of macroscopic material properties by the homogenization method in consideration of use environment

TERADA Kenjiro, WATANABE Ikumu, KURUMATANI Mao

The Proceedings of The Computational Mechanics Conference　2005　(0)　277-278　2005
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmecmd.2005.18.277 　

ISSN： 1348-026X
Voxel有限要素法を用いた超音波伝播シミュレーション

平元邦幸, 生出佳, 山田真幸, 寺田賢二郎

第54回理論応用力学講演会講演論文集(NCTAM2005)　87-88　2005

DOI： 10.11345/japannctam.54.0.32.0 　
ボクセル有限要素法による鋼構造物の超音波シミュレーション

山田真幸, 平元邦幸, 生出佳, 寺田賢二郎

計算工学講演会論文集　2　2005
Topology optimization considering geometrical nonlinearities by the CAMD method

Matsui Kazumi, Terada Kenjiro, Nishiwaki Shinji

The Computational Mechanics Conference　2004　(17)　413-414　2004/11/17
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
Structural Optimization of Mechanical Resonators

Maeda Yasunori, Nishiwaki Shinji, Izui Kazuhiro, Yoshimura Masataka, Matsui Kazumi, Terada Kenjiro

The Computational Mechanics Conference　2004　(17)　411-412　2004/11/17
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X

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This paper proposes a structural topology optimization method for obtaining mechanical resonators incorporating desired dynamic characteristics. First a new type of homogenization design method is introduced, in which the continuous material distributions are assumed using a continuous interpolation function at each node, in order to overcome numerical instabilities. Next, three design requirements to implement specific dynamic characteristics in the mechanical structures are clarified, namely eigen-frequency matching, eigen-mode control, and stiffness, and the corresponding objective functions are formulated. An optimization algorithm is developed using Sequential Linear Programming (SLP). Finally, several examples are provided in order to confirm the usefulness of the generated optimal designs for mechanical resonators.
Multi-scale analyses by the finite cover method for thermo-elastostatic problems

KURUMATANI Mao, TERADA Kenjiro

The Computational Mechanics Conference　2004　(17)　315-316　2004/11/17
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
A CAMD method for Topology Optimization in Finite Deformation Problems Invited

Matsui, K, Terada, K, Nishiwaki, S

International Workshops on Advances in Computational Mechanics, Tokyo, Japan　108　2004/10
動的機能をもつ機械構造物のトポロジー最適化 Invited

前田泰典, 泉井一浩, 西脇眞二, 吉村允孝, 松井和己, 寺田賢二郎

日本機械学会年次大会 Vol.7，北海道，日本　221-222　2004/09
マルチスケール解析

寺田賢二郎

Journal of the Japan Society of Mechanical Engineers　107　(1029)　592-592　2004/08/05
Publisher: Japan Society for Mechanical Engineers
ISSN： 0021-4728
Approximation properties of generalized elements in finite cover method

KURUMATANI Mao, TERADA Kenjiro

Transactions of the Japan Society for Computational Engineering and Science　6　127-136　2004/05/20
Publisher: 日本計算工学会
ISSN： 1344-9443
Survey of Topology Optimization for Finite Deformation Problems

TERADA Kenjiro

Annual report of the Society for the Promotion of Construction Engineering　39　73-80　2004/04/01
Publisher: Tohoku University
ISSN： 0288-9994
Error Estimation and Improvement of Accuracy in the Finite Element Analyses in Geotechnical Engineering

TERADA Kenjiro, YAMADA Masayuki

Annual report of the Society for the Promotion of Construction Engineering　39　68-72　2004/04/01
Publisher: Tohoku University
ISSN： 0288-9994
Development of nondestructive evaluation method for infrastructures

YAMADA Masayuki, TERADA Kenjiro

Annual report of the Society for the Promotion of Construction Engineering　39　81-88　2004/04/01
Publisher: Tohoku University
ISSN： 0288-9994
均質化法に基づく非線形マルチスケール解析--現状と課題

寺田賢二郎, 渡邊育夢

計算数理工学レビュー　2004　(1)　1-22　2004/03
Publisher: 日本計算数理工学会
ISSN： 1348-7353
Possibility and limitation of numerical analyses based on crystal plasticity : Macro-scale material properties evaluated from micro-scale structural characteristics

TERADA Kenjiro

材料とプロセス : 日本鉄鋼協会講演論文集 = Current advances in materials and processes : report of the ISIJ meeting　17　(3)　404-407　2004/03/01

ISSN： 0914-6628
有限被覆法による非均質材料の非線形解析

寺田賢二郎, 車谷麻緒, 石井建樹, 浅井光輝

理論応用力学講演会講演論文集　53rd　485-486　2004/01/27

DOI： 10.11345/japannctam.53.0.145.0 　
Evaluation of grain effects by multi-scale modeling based on homogenization method for polycrystalline metals

WATANABE Ikumu, MARUYAMA Atsushi, TERADA Kenjiro, AKIYAMA Masayoshi

The Proceedings of The Computational Mechanics Conference　2004　(0)　707-708　2004
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmecmd.2004.17.707 　

ISSN： 1348-026X
Topology optimization method by continuous approximation of material distribution

Matsui Kazumi, Terada Kenjiro, Nishiwaki Shinji, Ishii Keizo

The Computational Mechanics Conference　2003　(16)　887-888　2003/11/22
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
Structural Topology Optimization of Compliant Mechanisms Considering the Ratio of the Displacement at the Input Point to the Displacement at the Output Point

Hosoyama Akira, Nishiwaki Shinji, Izui Kazuhiro, Yoshimura Masataka, Matsui Kazumi, Terada Kenjiro

The Computational Mechanics Conference　2003　(16)　881-882　2003/11/22
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
Structural Topology Optimization of Function-Oriented Structure with Design Objectives Concerning Vibrational Characteristics

Maeda Yasunori, Nishiwaki Shinji, Izui Kazuhiro, Yoshimura Masataka, Matsui Kazumi, Terada Kenjiro

The Computational Mechanics Conference　2003　(16)　885-886　2003/11/22
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
Generalization of Finite Element Methods and Finite Cover Method

TERADA Kenjiro

Journal of the Japan Society for Computational Engineering and Science　8　(4)　783-787　2003/10/31
Publisher: 日本計算工学会
ISSN： 1341-7622
有限要素法の一般化と有限被覆法

寺田賢二郎

Journal of the Japan Society for Computational Engineering and Sciences　8　(4)　5-9　2003/10/31
Publisher: Japan Society for Computational Engineering and Sciences
機械式レゾネーターの最適設計（材料分布の連続性を考慮したトポロジー最適化を用いた場合） Invited

前田泰典, 泉井一浩, 西脇眞二, 吉村允孝, 松井和己, 寺田賢二郎

第13回設計工学・システム部門講演会，日本機械学会，金沢，日本　343-346　2003/10
ミクロからマクロを予測する

kenjiro Terada

Civil Engineers　88　(8)　23-24　2003/08/15
Publisher: Society of Civil Engineers
ISSN： 0021-468X
せん断帯分岐と不連続変形による供試体のひずみ局所化の有限変形解析

山川優樹, 池田清宏, 寺田賢二郎, 堤成一郎, 鳥居邦夫

地盤工学研究発表会発表講演集　38th　(0)　1139-1140　2003/06/06
Publisher: 公益社団法人地盤工学会
DOI： 10.11512/jiban.JGS38.0.1139.0 　

ISSN： 1342-2863

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We present numerical analysis on strain localization in soil specimens due to shear band bifurcation and discontinuous slip. Kinematics and criterion for shear band mode at finite strain are briefly introduced, and a finite element method with enhanced mode to simulate discontinuous slip in the post-bifurcation stage is employed. Examination of the bifurcation criterion reveals that the shear band bifurcation is possible even in the associative strain-hardening materials. Several numerical results show the significance of the consideration to the shear band kinematics in numerical analysis for strain localization problems.
有限被覆法による不連続面進展解析

浅井光輝, 寺田賢二郎

計算工学講演会論文集　8　(1)　97-100　2003/05/19

ISSN： 1342-145X
界面要素を用いた有限被覆法とその弾塑性問題への適用

車谷麻緒, 浅井光輝, 寺田賢二郎

計算工学講演会論文集　8　(1)　101-104　2003/05/19

ISSN： 1342-145X
非均質脆性材料に対するマルチスケール解析法

浅井光輝, 寺田賢二郎

計算工学講演会論文集　8　(1)　239-242　2003/05/19

ISSN： 1342-145X
固定メッシュを用いた有限被覆法による大変形解析

石橋慶輝, 寺田賢二郎, 浅井光輝

計算工学講演会論文集　8　(2)　585-588　2003/05/19

ISSN： 1342-145X
非局所型ボクセル有限要素法の開発とその破壊挙動解析への適用

山岸道弘, 浅井光輝, 寺田賢二郎

計算工学講演会論文集　8　(1)　109-112　2003/05/19

ISSN： 1342-145X
Development of multi‐scale discrete deformation analysis based on a nonlinear homogenization theory.

浅井光輝, 寺田賢二郎

理論応用力学講演会講演論文集　52nd　487-488　2003/01/27
統合地震シミュレータのプロトタイプ開発に関する基礎研究

寺田賢二郎, 市村強, 堀宗朗, 山川貴弘

土木学会年次学術講演会講演概要集(CD-ROM)　58th　(Disk 1)　2003
震災情報高度化を目指した統合震災シミュレーター開発のための基礎研究

市村強, 寺田賢二郎, 堀宗朗, 山川貴弘

構造物の安全性および信頼性　5　2003
高分解能強震動情報とGIS・CADデータを用いた震災評価システムのプロトタイプ

市村強, 山川貴弘, 寺田賢二郎, 堀宗朗

計算工学講演会論文集　8　(2)　2003

ISSN： 1342-145X
Analysis of polycrystalline metals by multi-scale modeling based on homogenization theory

WATANABE Ikumu, TERADA Kenjiro, MATSUI Kazumi, AKIYAMA Masayoshi, NEISHI Yutaka

The Proceedings of The Computational Mechanics Conference　2003　(0)　605-606　2003
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmecmd.2003.16.605 　

ISSN： 1348-026X
Global-local analysis with interface element using voxel model for local heterogeneous structures

Takeshi Ishii, Kenjiro Terada, Takeshi Kyoya, Michihiro Yamagishi, Yuji Kishino

J. Appl. Mech., JSCE　6　141-150　2003
Multi-scale simulation without macro-scale constitutive models

TERADA Kenjiro, ASAI Mitsuteru, MATSUI Kazumi

日本機械学会材料力学部門講演会講演論文集　2003　117-120　2003
Publisher: 日本機械学会

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We present the micro-macro coupling analysis method that does not necessitates the macroscale constitutive relations. The method has been applied to various kinds of heterogeneous materials and known as the multi-scale finite element methods based on the mathematical homogenization theory. We here apply the method to heterogeneous elastic-plastic composites and brittle heterogeneous ceramics, and provide several illustrative numerical examples. In particular, the latter application involves the replacement of the macroscopic strain by the non-local macroscopic strain to achieve the mesh impendency in numerical analysis with local damages.
地盤力学におけるマイクロメカニックスとマクロメカニックスの関係（その２）

堀宗朗, 寺田賢二郎, 京谷孝史, 金子賢治

Soils and Foundations　51　(1)　31-36　2003/01/01
Publisher: The Japanese Geotechnical Society
ISSN： 0041-3798
Macroscopic behavior of elasticplastic heterogeneous solids characterized by the interfacial dobonding in microscale

MATSUI Kazumi, TERADA Kenjiro

The Computational Mechanics Conference　2002　(15)　279-280　2002/10/30
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
非均質材料のマルチスケール解析と塑性流動則におけるポテンシャル面の尖り効果

堤成一郎, 松井和己, 寺田賢二郎

日本機械学会計算力学講演会講演論文集　15th　(15)　191-192　2002/10/30
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
Consistentトポロジー最適化手法とその有限変形問題への適用 Invited

松井和己, 寺田賢二郎, 西脇眞二

第5回最適化シンポジウム，日本機械学会，京都，日本　247-252　2002/10
ミクロ構造不安定性を考慮した脆性材料の強度評価法

浅井光輝, 寺田賢二郎

土木学会年次学術講演会講演概要集(CD-ROM)　57th　CS7-016　2002/09/01
NONLINEAR MULTI-SCALE ANALYSIS OF CELLULAR SOLIDS WITH FRAME ELEMENTS

OOUE Ken, SAIKI Isao, TERADA Kenjiro, NAKAJIMA Akinori

7　(2)　505-508　2002/05/20

ISSN： 1342-145X
Derermination of mechanical properties in microstructures by the response surface methodology

KUSAKA Keiichi, MATSUI Kazumi, TERADA Kenjiro

7　(2)　481-484　2002/05/20

ISSN： 1342-145X
MICRO-SCALE ANALYSIS OF DISCRETE SYSTEMS WITH POTENTIAL FUNCTION

KANKE Shigeri, SAIKI Isao, NAKAJIMA Akinori, TERADA Kenjiro

7　(2)　501-502　2002/05/20

ISSN： 1342-145X
Application of Hierarchical Modeling to Dynamic Finite Element Analysis of Structures

OIDE Kai, TERADA Kenjiro, ICHIMURA Tsuyoshi

7　(2)　533-534　2002/05/20

ISSN： 1342-145X
Multi-scale analysis of elastic-plastic bodies with interfacial debonding

MATSUI Kazumi, TERADA Kenjiro

7　(2)　513-516　2002/05/20

ISSN： 1342-145X
MULTI-SCALE EVALUATION METHOD FOR STRENGTH OF BRITTLE MATERIALS

ASAI Mitsuteru, TERADA Kenjiro

計算工学講演会論文集　7　(2)　489-492　2002/05/20

ISSN： 1342-145X
THE IMAGE-BASED FCM USING A MULTI-COVER SYSTEM

YAMAGISHI Michihiro, ASAI Mitsuteru, TERADA Kenjiro

計算工学講演会論文集　7　(2)　541-544　2002/05/20

ISSN： 1342-145X
高分解能強震動情報と電子仮想都市を用いた統合震災シミュレータの開発

市村強, 堀宗朗, 楊芳, 寺田賢二郎

土木学会年次学術講演会講演概要集(CD-ROM)　57th　2002
Development of Unified Earthquake Disaster Simulator based on Digital Virtual Town and Strong Motion Simulator with High Spatial Resolution.

市村強, 堀宗朗, YANG F, 寺田賢二郎

日本地震工学シンポジウム論文集　11th　2002
Multiscale analysis of macroscpic material nonlinear behavior due to microscopic brittle failure

ASAI Mitsuteru, TERADA Kenjiro

The Proceedings of The Computational Mechanics Conference　2002　(0)　277-278　2002
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmecmd.2002.15.277 　

ISSN： 1348-026X
110 The influence of microstructure for the macroscopic elastic-plastic behavior of steel

MATSUI Kazumi, OIKAWA Kenji, TERADA Kenjiro, AKIYAMA Masayoshi, KUBOKI Takashi

The Computational Mechanics Conference　2001　(14)　19-20　2001/11/27
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
マルチスケール法

寺田賢二郎

計算工学　6　(4)　360-360　2001/10/31

ISSN： 1341-7622
非均質構造材料のマルチスケールモデリング

斉木功, 寺田賢二郎

Journal of the Japan Society for Computational Engineering and Sciences　6　(4)　361-363　2001/10/31
Publisher: Japan Society for Computational Engineering and Sciences
ISSN： 1341-7622
特集企画趣旨

寺田賢二郎

Journal of the Japan Society for Computational Engineering and Sciences　6　(4)　360-360　2001/10/31
Publisher: Japan Society for Computational Engineering and Sciences
イメージベースFCMの開発とその性能評価

山岸道弘, 浅井光輝, 寺田賢二郎

土木学会年次学術講演会講演概要集第1部　56th　(B)　476-477　2001/09/01
ラチスモデルによる鉄筋コンクリート構造のイメージベース解析

浅井光輝, 寺田賢二郎, 池田清宏

土木学会年次学術講演会講演概要集第5部　56th　962-963　2001/09/01
Post-bifurcation analysis on diffuse bifurcation mode and mode analysis on discontinuous localization of compression test specimens

YAMAKAWA Yuuki, IKEDA Kiyohiro, TERADA Kenjiro, TORII Kunio

6　(2)　635-638　2001/05/30

ISSN： 1342-145X
A study on the macroscopic elastic-plastic material behavior of steel induced by its microstructures

OIKAWA Kenji, MATSUI Kazumi, TERADA Kenjiro, AKIYAMA Masayosi, KUBOKI Takashi

6　(2)　453-454　2001/05/30

ISSN： 1342-145X
A consideration on the formulation of micro-scale analyses with frame element

OOUE Ken, SAIKI Isao, TERADA Kenjiro, NAKAJIMA Akinori

6　(2)　435-438　2001/05/30

ISSN： 1342-145X
A MULTISCALE ANALYSIS METHOD FOR FINITE DEFORMATION ELASTOPLASTICITY

TERADA Kenjiro, MATSUI Kazumi, SAIKI Isao, YAMAKAWA Yuki

6　(2)　443-444　2001/05/30

ISSN： 1342-145X
A STUDY ON THE BOUNDARY CONDITION OF MULTI-PHASE MATERIALS FOR A FCM

ASAI Mitsuteru, TERADA Kenjiro, YAMAGISHI Michihiro, IKEDA Kiyohiro

計算工学講演会論文集　6　(2)　483-486　2001/05/30
Publisher: 日本計算工学会
ISSN： 1342-145X
ESTIMATE OF PERIODICITY OF MICROSTRUCTURE UNDERGOING GEOMETRICAL INSTABILITY AND MULTI-SCALE MODELING OF MATERIAL INSTABILITY

SAIKI Isao, TERADA Kenjiro, IKEDA Kiyohiro, HORI Muneo

計算工学講演会論文集　6　(2)　431-434　2001/05/30

ISSN： 1342-145X
三角形高次要素を用いたトポロジー最適化手法とその大変形問題への適用 Invited

松井和己, 寺田賢二郎, 西脇眞二, 石橋慶輝

計算工学講演会，Vol. 6　737-738　2001/05
構造物のトポロジー最適設計におけるイメージ解析モデルに関する考察 Invited

石橋慶輝, 松井和己, 寺田賢二郎, 西脇眞二

計算工学講演会、Vol.6　735-736　2001/05
Development of an image‐based FCM and estimate on its performance.

浅井光輝, 寺田賢二郎, 加藤和弘

理論応用力学講演会講演論文集　50th　159-160　2001/01/23
A Homogenization-based Multi-Scale Analysis Method for Some Classes of Nonlinear Problems

TERADA Kenjiro, MATSUI Kazumi

The Computational Mechanics Conference　2000　(13)　751-752　2000/11/27
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
An evaluation method of the macroscopic constitutive relation based on the multi-scale modeling

MATSUI Kazumi, TERADA Kenjiro, KYOYA Takashi, IWAKUMA Tetsuo

The Computational Mechanics Conference　2000　(13)　815-816　2000/11/27
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
Efficient approach by parallel processing for the nonlinear multi-scale analysis

MATSUI Kazumi, TERADA Kenjiro, YUGE Kohei

The Computational Mechanics Conference　2000　(13)　787-788　2000/11/27
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
ラチスモデルによる鉄筋コンクリート解析

浅井光輝, 寺田賢二郎, 池田清宏

土木学会年次学術講演会講演概要集第5部　55th　1092-1093　2000/08/31
計算力学のエッセンス－有限要素法を中心として－

Kenjiro Terada

Civil Engineers　85　30-34　2000/08/01
Publisher: Society of Civil Engineers
A consideration on application of frame element to micro-structure in multi-scale analysis of cellular solids

OOUE Ken, SAIKI Isao, NAKAJIMA Akinori, TERADA Kenjiro

Proceedings of the conference on computational engineering and science　5　(2)　745-748　2000/05/24
Publisher: 日本計算工学会
ISSN： 1342-145X
A formulation for multi-scale modeling of cellular solids by means of generalized convergence theorem

SAIKI Isao, TERADA Kenjiro, IKEDA Kiyohiro

Proceedings of the conference on computational engineering and science　5　(2)　749-752　2000/05/24
Publisher: 日本計算工学会
ISSN： 1342-145X
BIFURCATION MODE AND POST-BIFURCATION ANALYSIS OF ELASTO-PLASTIC BODY UNDER COMPRESSION

YAMAKAWA Yuuki, IKEDA Kiyohiro, TERADA Kenjiro

Proceedings of the conference on computational engineering and science　5　(2)　649-652　2000/05/24
Publisher: 日本計算工学会
ISSN： 1342-145X
Multi-scale analysis using the parallel computer of cluster type

MATSUI Kazumi, TERADA Kenjiro, YUGE Kohei

5　(2)　763-764　2000/05/24

ISSN： 1342-145X
A consideration for the nonlinear multi-scale analysis with finite element method

MATSUI Kazumi, TERADA Kenjiro

5　(2)　765-766　2000/05/24

ISSN： 1342-145X
Macroscopic constitutive relation of the elasto-plastic bodies based on the multi-scale modeling

MATSUI Kazumi, TERADA Kenjiro, KYOYA Takashi, IWAKUMA Tetsuo

Proceedings of the conference on computational engineering and science　5　(2)　771-774　2000/05/24
Publisher: 日本計算工学会
ISSN： 1342-145X
MULTISCALE ANALYSIS OF GRANULAR MATERIALS

KANEKO Kenji, TERADA Kenjiro, KYOYA Takashi, KISHINO Yuji

Proceedings of the conference on computational engineering and science　5　(2)　775-778　2000/05/24
Publisher: 日本計算工学会
ISSN： 1342-145X
ANALYSIS OF SHARE FRACTURE OF RAINFORCED CONCRETE BEAMS BY LATTICE MODEL

ASAI Mitsuteru, TERADA Kenjiro, IKEDA Kiyohiro

Proceedings of the conference on computational engineering and science　5　(2)　703-706　2000/05/24
Publisher: 日本計算工学会
ISSN： 1342-145X
Development of Stability-Evaluation System for Rock Masses by Combining Material and Structural Analyses

TERADA Kenjiro

Annual report of the Society for the Promotion of Construction Engineering　35　102-103　2000/04/01
Publisher: Tohoku University
ISSN： 0288-9994
Failure Simulations of Structural Concrete Using a Lattice Model

ASAI Mitsuteru, TERADA Kenjiro, IKEDA Kiyohiro

The Proceedings of The Computational Mechanics Conference　2000　(0)　73-74　2000
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmecmd.2000.13.73 　

ISSN： 1348-026X
MICROSTRUCTURAL MATERIAL DESIGN USING FFT AND DIGITAL IMAGES

SUZUKI Katsuyuki, TERADA Kenjiro, OHTSUBO Hideomi

Proceedings of the conference on computational engineering and science　2　(3)　1099-1102　1999/05/28
Publisher: 日本計算工学会
ISSN： 1342-145X
HOMOGENIZATION ALGORITHM BY USING FFT AND DIGITAL IMAGES

TERADA Kenjiro, SUZUKI Katsuyuki, OHTSUBO Hideomi

Proceedings of the conference on computational engineering and science　2　(3)　1095-1098　1999/05/28
Publisher: 日本計算工学会
ISSN： 1342-145X
CONSTITUTIVE MODEL DERIVED FROM THE HOMOGENIZATION METHOD AND ITS NUMERICAL ANALYSES

TERADA Kenjiro, ITO Takashi, KIKUCHI Noboru

Proceedings of the conference on computational engineering and science　2　(3)　1119-1122　1999/05/28
Publisher: 日本計算工学会
ISSN： 1342-145X
HOMOGENIZATION THEORY FOR SOLID-FLUID MIXTURES AND ITS NUMERICAL ANALYSES

TERADA Kenjiro, ITO Takashi, KIKUCHI Noboru

Proceedings of the conference on computational engineering and science　2　(3)　1115-1118　1999/05/28
Publisher: 日本計算工学会
ISSN： 1342-145X
MULTISCALE MODELING OG FISSURED MEDIA

MANO Atsushi, TERADA Kenjiro, KYOYA Takashi

Proceedings of the conference on computational engineering and science　4　(2)　715-718　1999/05/26
Publisher: 日本計算工学会
ISSN： 1342-145X
ANALYSIS OF PERMEABILITY OF FIBROUS COMPOSITES BY THE HOMOGENIZATION METHOD

YOSHIOKA Tomomi, TAKANO Naoki, TERADA Kenjiro, ZAKO Masaru

Proceedings of the conference on computational engineering and science　4　(2)　733-736　1999/05/26
Publisher: 日本計算工学会
ISSN： 1342-145X
Appropriate model of unite cell for multi-scale analyses of cellular solids with local instability

SAIKI Isao, TERADA Kenjiro, IKEDA Kiyohiro

Proceedings of the conference on computational engineering and science　4　(2)　745-748　1999/05/26
Publisher: 日本計算工学会
ISSN： 1342-145X
A CLASS OF GENRAL ALGORITHMS FOR NONLINEAR MULTISCALE ANALYSIS

TERADA Kenjiro, MATSUI Kazumi, SAIKI Isao, KIKUCHI Noboru

Proceedings of the conference on computational engineering and science　4　(2)　741-744　1999/05/26
Publisher: 日本計算工学会
ISSN： 1342-145X
Analysis of Permeability of Textile Composite Materials by the Homogenization Method

TAKANO Naoki, TERADA Kenjiro, ZAKO Masaru, YOSHIOKA Tomomi

24　91-92　1999/01
The Accuracy Control of Voxel Analysis Using Finite Cover Method

OHTSUBO Hideomi, SUZUKI Katsuyuki, TERADA Kenjiro, MIN Seungjae, JIN Chuanrong, NAKANISHI Katsuyoshi

3　(2)　387-388　1998/05/26

ISSN： 1342-145X
VISCO-ELASTIC ANALYSIS FOR SOLID-FLUID MIXTURES BASED ON HOMOGENIZATION THEORY

IZUMIYA Takashi, UO Tomoyuki, KASHIYAMA Kazuo, TERADA Kenjiro

Proceedings of the conference on computational engineering and science　3　(3)　1031-1034　1998/05/26
Publisher: 日本計算工学会
ISSN： 1342-145X
CHARACTERIZATION OF THE PERMEABILITY OF DISCOUTINUOUS ROCK MASS BY THE HOMOGENIZATION METHOD

TERADA Kenjiro, KYOYA Takashi, WATANABE Tomoyasu

Proceedings of the conference on computational engineering and science　3　(3)　1015-1018　1998/05/26
Publisher: 日本計算工学会
ISSN： 1342-145X
SIMULATION FOR REPRESENTATIVE VOLUME ENELEMETS AND MULTI-SCALE CONVERGENCE

TERADA Kenjiro, HORI Muneo, KYOYA Takashi, KIKUCHI Noboru

Proceedings of the conference on computational engineering and science　3　(3)　1019-1022　1998/05/26
Publisher: 日本計算工学会
ISSN： 1342-145X
Homogenization method as a representative volume element method using period boundary condition.

寺田賢二郎, 堀宗朗, 京谷孝史

土木学会年次学術講演会講演概要集第1部　53rd　1998
4th USNCCM

KASHIYAMA Kazuo

2　(4)　261-263　1997/12/25

ISSN： 1341-7622
MANIFOLD METHOD CONTROLLING ACCURACY USING FINITE COVERS

OHTSUBO Hideomi, SUZUKI Katsuyuki, TERADA Kenjiro, NAKANISHI Katsuyoshi

Proceedings of the conference on computational engineering and science　2　(2)　399-402　1997/05/28
Publisher: 日本計算工学会
ISSN： 1342-145X
ANALYSIS METHOD FOR SOLID STRUCTURES USING MULTIPLE VOXEL INFORMATION

SUZUKI Katsuyuki, TERADA Kenjiro, OHTSUBO Hideomi, YONESATO Naoki

Proceedings of the conference on computational engineering and science　2　(2)　395-398　1997/05/28
Publisher: 日本計算工学会
ISSN： 1342-145X
1st JSCES Conference

TAKEUCHI Norio, TERADA Kenjiro

1　(3)　182-184　1996/09/30

ISSN： 1341-7622
均質化法による複合材料の非線形解析

寺田賢二郎

構造工学における数値解析シンポジウム論文集, 1995　19　231-236　1995
Structural Optimization Based on the LevelSet Method Using the Finite Cover Method Invited

Ikeuchi, S, Yamasaki, S, Nishiwaki, S, Izui, K, Yoshimura, M, Kurumatani, M, Terada, K

Third Asian-Pacific Congress on Computational Mechanics in conjunction with Eleventh International Conference on Enhancement and Promotion of Computational Methods in Engineering and Science, Kyoto, Japan

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Books and Other Publications 10

例題で学ぶ有限要素解析

車谷, 麻緒, 寺田, 賢二郎, 非線形CAE協会

森北出版　2021/10

ISBN: 9784627486614
数値材料試験 : 有限要素法によるマルチスケール解析

寺田, 賢二郎, 平山, 紀夫, 山本, 晃司

丸善出版　2021/07

ISBN: 9784621306338
計算力学 : 有限要素法の基礎（第2版）

日本計算工学会, 竹内, 則雄, 樫山, 和男, 寺田, 賢二郎

森北出版　2012/12

ISBN: 9784627918023
Computational Methods for Plasticity

寺田賢二郎

森北出版株式会社　2012/06/29
金属材料の加工と組織

Kenjiro Teradam, Yasuhiro Nakayama

共立出版　2010/03

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森永正彦・古原忠・戸田裕之編
いまさら聞けない計算力学の常識

寺田賢二郎, 西村直志, 阿部和久, 樫山和男, 車谷麻緒, 渡辺育夢, 富山潤, 岡澤重信

丸善　2008/11

ISBN: 9784621080221
計算力学ハンドブック

Kenjiro Terada

朝倉書店　2007/06

ISBN: 9784254231120
竹内則雄，樫山和男，寺田賢二郎，計算力学 ―有限要素法の基礎―

竹内則雄, 樫山和男, 寺田賢二郎

2003/09
Introduction to the method of homogenization

寺田賢二郎, 菊池昇

2003/07
Modeling in Geomechanics

Kenjiro TERADA, Takashi ITO, Noboru Kikuchi

2000

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Presentations 1

Finite Cover Method for Physically and Geometrically Nonlinear Problems International-presentation

Second International Workshop Meshfree Methods for Partial Differential Equations　2003/09/15

Industrial Property Rights 3

気液2相流解析方法

原田岳, 藤内誠, 寺田賢二郎, 進藤和弥

Property Type: Patent
均質化法を用いる構造解析方法，均質化法を用いる構造解析装置及び均質化法を用いる構造解析プログラム

原田岳, 藤内誠, 寺田賢二郎, 山田真幸, 脇坂洋平

Property Type: Patent
連続的材料分布を用いた位相最適化手法

石井惠三, 松井和己, 寺田賢二郎, 西脇眞二

Property Type: Patent

Research Projects 40

Material point method for deformation and flow analyses and its application to sediment disasters Competitive

System: Contract Research

2017/04 - Present
Double damage model for evaluation of residual strength of steel structures subjected to earthquake excitations Competitive

System: Contract Research

2016/04 - Present
Development of multistage failure simulations for disaster risk evaluation Competitive

System: Grant-in-Aid for Scientific Research

2016/04 - Present
Space-time multi-scale fracture mechanics model in consideration of environmental factors Competitive

System: Cooperative Research

2015/04 - Present
Multiscale numerical testing for assessment of interaction between tsunami run-up and structures Competitive

System: Grant-in-Aid for Scientific Research

2013/04 - Present
Re-examination of effects of heterogeneity on the strength of concrete Competitive

System: Grant-in-Aid for Scientific Research

2010/04 - Present
Development of prediction method for strenght and deterioration of SOFC Competitive

System: New Energy Technology Research and Development

2007/09 - Present
Development of Multiscale CAE software Competitive

System: The Other Research Programs

2006/04 - Present
Multiscale analysis of rubber Competitive

System: The Other Research Programs

2003/04 - Present
Studies on topology optimization and optimal design Competitive

System: The Other Research Programs

2001/04 - Present
Development of Generalized Finite Element Method Competitive

System: The Other Research Programs

2000/04 - Present
Analysis method fo macroscopic failure with microscopic instabilities Competitive

System: The Other Research Programs

2000/04 - Present
Effects of microstructures of on the macroscopic material properties of metals Competitive

System: Funded Research

1998/04 - Present
A novel approach for risk reduction of heavy rain disaster using a digital shadow with physics-based modeling

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2024/04/01 - 2028/03/31
High-definition Virtualization of sediment disaster by highly accurate and efficient numerical simulation

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2022/04/01 - 2026/03/31
Construction of creative design method of new functional structures using crack initiation/growth and finite deformation

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory)

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: Kyoto University

2022/06/30 - 2025/03/31
Multi-scale analysis based on statistical mechanics for materials informatics

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: University of Tsukuba

2022/04/01 - 2025/03/31
Slope stability analysis during heavy rain that directly solve different spatial scales of a single slope and a wide area

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2021/04/01 - 2024/03/31
Numerical simulation of ground motion by synthesized representation of transition between solid and liquid

Terada Kenjiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2019/04/01 - 2022/03/31

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We develop a semi-implicit MPM to properly express the mechanical behavior of unsaturated soil based on Biot's mixture theory. The new contribution of this study is the incorporation of the fractional-step method into the MPM to solve the pore water pressure implicitly, which improves the numerical stability and computational efficiency. Moreover, the time increment can be determined without considering the magnitude of water permeability because the interaction between solid and liquid phases is evaluated using the intermediate velocity. Several numerical examples are presented to demonstrate the capability and performance of the proposed method for analyses of unsaturated soils. In particular, a validation analysis is carried out using a model experiment of infiltration-induced landslide.
An example of Specific V&V for slope disaster simulations

Moriguchi Shuji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2018/04/01 - 2021/03/31

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It’s generally difficult to discuss the accuracy and reliability in disaster simulations. On the other hand, recently, V&V (Verification & Validation) of numerical simulations has been emphasized and widely discussed. The purpose of this study is to develop the information that are necessary for V&V of rockfall analysis and sediment flow analysis using the discrete element method (DEM). Specifically, information on the following three topics was studied based on the results of DEM analysis: setting up benchmark problems, quantification of the effect of uncertainties in DEM simulations, and frameworks for reducing computational cost.
Development of multiscale multi-physics rock mechanics for swelling rock mass

Kyoya Takashi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2016/04/01 - 2020/03/31

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In order to resolve the problem of deterioration of underground structures after construction due to swelling of rock mass we have developed a new multiscale multi-physics rock mechanics approach. We carried out laboratory swelling tests of montmorillonite and formulated a thermodynamics model for the swelling behavior. We also formulated a numerical analysis model based on the modified Cam-Clay model that can predict deteriorating strength and stiffness of rock mass along with a rigorous return-mapping algorism. Then we developed a multiscale multi-physics analysis model for swelling rock mass by Incorporating the thermodynamics swelling model into the Cam-Clay type model. A series of analyses of a tunnel within a swelling rock mass predicted displacement and stress distribution around the tunnel in good agreement with measured data. We conclude therefore the validity and effectiveness of this proposed multiscale multi-physics rock mechanics theoretical model.
Stochastic homogenization for uncertainty quantification in multiscale analysis

Masamune Jun

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (C)

Institution: Hokkaido University

2016/07/19 - 2019/03/31

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We established a homogenization theory, more precisely, the H-convergence theory on general Riemannian manifolds. The main theoretical result in the project was to show a compactness result for a family of diffusion coefficients and that H-convergence implies Mosco convergence. As a consequence, there is a weak converging sequence of Brownian motions provided the tightness. As applications of homogenization theory, we constructed a mathematical model for micro-fibers and analyzed it, and, discussed the results obtain by the averaging methods and homogenization theory. We also studied the Carbon Fiber Reinforced Polymer Composites (CFRP) using the homogenization theory and numerical analysis. In particular, we proposed several new methods to evaluate the strengths of CFRP and conducted tests using numerical methods combined with homogenization theory.
Topology optimization of metallic polycrystalline microstructure to improve strength and deformability

Kato Junji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

2016/04/01 - 2019/03/31

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Ductility is the most important mechanical characteristic for metallic materials and has co-relation with the strength and deformability. Those performances are determined by the microstructure, namely crystalline structure. In the meanwhile, it is well known that topology optimization is a powerful design tool to maximize the mechanical performance of structures/materials by applying computers. The present study developed a material design method to maximize the mechanical performance of polycrystalline microstructure, such as stiffness, ductility and thermal conductivity, and verified its usefulness by a series of numerical examples.
Material design applying numerical material testing and decoupling multiscale topology optimization

Kato Junji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2014/04/01 - 2017/03/31

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It is well known that the structural behavior strongly depends on the material microstructure. Recently, production technology enables to control/manufacture the microstructure to a degree and this kind of topics has been paid attention in world wide, especially in the research for advanced materials. However, most of them take empirical approaches strongly relying on the experiments. For the best of our knowledges, these approaches cannot lead to the truly optimal design. The present study proposed topology optimization method to provide an optimal microstructure numerically for maximizing structural performance and eventually the usability and versatility of the proposed method was verified by the series of numerical examples. Specifically, we developed a method to optimize microstructure topology of hyperelastic composite material and also to optimize a metallic crystalline structure to maximize the macroscopic structural performance.
Multi-scale non-destructive simulation using an inverse homogenization method

Takashi Kyoya, KATO Junji, TERADA Kenjiro, NAKAHATA Kazuyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2012/04/01 - 2016/03/31

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This research takes numerical approaches; EFIT and the inverse homogenization method using the finite element method; aimed at identifying the distribution of micro-cracks, which cause degradation of, and damage to, structures. The research proposed a series of methods using optimization algorithms to calculate the micro-crack distribution with material stiffness equivalent to that of the given anisotropic material, and examined how well the methods modeled the distribution. While previous studies on non-destructive testing simulation by means of topology optimization are able to identify only a few damaged parts in material, this method is able to reproduce the directions of damaged parts, micro-cracks: this improvement is a step forward in the development of this field.
Anomalies of martensitic transformations appearing at very low temperatures-their origin and universality-

KAINUMA Ryosuke, MURAKAMI Yasukazu, OHNUMA Ikuo, OMORI Toshihiro, UMETSU Rie, TERADA Kenjiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (S)

Institution: Tohoku University

2010/04/01 - 2015/03/31

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Recently, some anomalies of martensitic transformations (MTs), such as strain glass in the NiTi alloy, thermal-transformation arrest phenomenon and heating-induced MT in NiCoMnIn alloys, have been found at very low temperatures. In this study, for the NiTi, NiCoMnIn, and CuAlMn alloys, basic physical and superelastic properties in the temperature region from 10 to 200 K were examined in order to clarify the origin and the universality of the abnormal properties. Through this project, the origins of them have almost been clarified and a candidate for superelastic materials, which can be operated at cryogenic temperatures, has been found in the CuAlMn alloy system.
Thermodynamics-based constitutive model for deformation twinning

TERADA Kenjiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2012/04/01 - 2014/03/31

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A thermodynamics-based constitutive model, which accounts for both crystallographic slip and deformation twinning, is developed for a single crystal of hcp metals within the framework of finite crystal plasticity. While the volume fractions of stress-free twin deformations are introduced as internal variables, the free-energy involves the bulk energy of separate phases and the surface energy at twin interfaces, which are introduced as functions of the internal variables, in addition to the standard hardening-related energy in crystal plasticity framework. After the formulation is described in detail, a series of numerical examples is presented to verify the performance of the proposed model in predicting the deformation twinning, the successive deformation process and the twinning-induced stress responses. The results are studied with reference to the theoretical consequences and the experimental results reported in the literature.
Multi-scale topology optimization for electromagnetic devices.

NISHIWAKI SHINJI, IZUI Kazuhiro, TERADA Kenjiro, NOMURA Tsuyoshi, OHKADO Makoto, HIRAYAMA Kohichi, DIAZ Alejandro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Kyoto University

2010/04/01 - 2014/03/31

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In this research, we constructed the structural optimization method for the microstructure design of artificial materials that consist of electromagnetic devices, and exhibit desirable properties such as electric permittivity or magnetic permeability, and the macrostructure design of electromagnetic devices such as cloaks and waveguides, based on the topology optimization method. We also developed the integrated design method for micro- and macro- level designs, aiming to achieve the creative design of electromagnetic devices that have new functionality or improved performance.
Optimal control of plastic material deformation

TAKASHI Kyoya, KATO Junji, TERADA Kenjiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2011 - 2013

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In the present study, we developed topology optimization of composite structure to maximize the energy absorption capacity in terms of two different materials. The most significant point in the present study is the derivation of accurate sensitivity of the objective function with respect to the design variable. We proposed the new approach capable of providing a highly accurate sensitivity by investigating the theoretical problems on other previous studies. The present method is considered as very efficient approach/method for the advance material design. The achievement is shown the two publication submitted to academic journal and six international/national congresses.
Multiscale topology optimization for maximizing energy absorption capacity of composites

KATO Junji, KYOYA Takashi, TERADA Kenjiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (C)

Institution: Tohoku University

2011 - 2013

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The purpose of the present study was to develop a multi-scale optimization which optimize topology of microstructure and/or kind of material of composites.In this achievement we developed successfully the new method, namely "multi-scale topology optimization". This method is based on the finite element method and significant approach from a view point of material design. In addition to above achievement, we also developed the new approach considering elastoplastic material model for composites and so-called phase-field method.These results were presented in six academic journals. So far, the four papers were published and the other two papers are under review process. Furthermore the results of the present study will be presented in the national and international congress totally 13 places.
Development of paleo-piezometer in elastic polymineralic rock using calcite twin

SAKAGUCHI Arito, YANAGISAWA Kazumichi, HISADA Makoto, KYOYA Takashi, TERADA Kenjiro, MINAGWA Hiroshi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Japan Agency for Marine-Earth Science and Technology

2010 - 2012

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It was believed impossible that to estimate paleo-stress from elastic rebounded polymineralic material as rock and concretes. The purpose of this study is to develop calcite-twin paleo-piezometer for rock mechanics and safety evaluation of concrete buildings. We succeeded that imaging of inner stress field of polycrystalline aggregates and paleo-piezometric analysis.
Development of a numerical method for large scale fluid-structure interaction problems based on multi-scale method using Eulerian description

KASHIYAMA Kazuo, TERADA Kenjiro, OKAZAWA Shigenobu, TANAKA Seizo

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Chuo University

2007 - 2009

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A new numerical simulation method which is applicable to large-scale and complicated fluid-structure interaction problem with free surface and large deformation has been presented in this research work. In order to treat the geometry of boundary, boundary condition and continuity condition at the boundary of fluid and structure, a finite cover method using Eulerian description based on fixed unstructured grid has been developed. The multi-scale method has been introduced to solve dynamic behavior of composite materials.
NODE-BASED FINITE ELEMENT METHOD FOR LARGE DEFORMATION ANALYSIS OF HETEROGENEOUS SOLIDS

TERADA Kenjiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (C)

Institution: Tohoku University

2007 - 2008
Development of an Integrated Early Warning and Structural Monitoring System to Real Time Earthquake Information

MOTOSAKA Masato, OHNO Susumu, SATO Takeshi, TERADA Kenjiro, SHINOZAWA Yotaro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2006 - 2007

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In this study, the development of the integrated earthquake early warning system and structural monitoring system has been performed to enhance its added value as well as reliability and utility. The investigated research items are; 1) Development of warning system by combining structural health monitoring and real time earthquake information, 2) Enhancement of accuracy of ground motion prediction considering local soil condition, 3) Effective utilization of EEWS in hospitals based on demonstration test, 4) Effective utilization of EEWS in schools based on demonstration test. Regarding the item 1), the online earthquake observation system was developed and installed at Oshika Branch Office (OBO) building located near the Pacific Ocean coast and a building of Civil Engineering and Building Science of Tohoku University in Sendai. The integrated earthquake early warning system has been demonstratively tested. Regarding the item 2), a prediction method based on the Artificial Neural Network (ANN) has been proposed to estimate more accurate ground motion prediction using the incoming waveform of the first portion of P-wave from OBO and also local soil conditions. The applicability of the proposed prediction method has been verified for the Miyagi-ken Oki earthquakes. Regarding the item 3), a questionnaire investigation was performed at Tohoku University Hospital to clarify the needs of RTEI and effective utilization system has been proposed. To perform demonstration test, a receiver of Real-Time Earthquake Information was installed at the hospital together with display and warning lamps in this study. Regarding the item 4), a animation of earthquake disaster simulation was made for the education mode of the prototype model and its utilization has been investigated. A questionnaire investigation was performed for total number of 649 schools in Miyagi prefecture and metropolitan area to grasp the needs from education site and to promote the utilization of EEWS in schools.
MULTI-SCALE MULTI-PHYSICS ANALYSIS OF DETERIORATION PROCESS IN REINFORCED CONCRETE

TERADA Kenjiro, KYOYA Takashi, YAMADA Masaki, ISHII Tateki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2005 - 2006

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We developed a multi-scale multi-physics analysis method for mass concentration diffusion and deformation in quasi-brittle materials such as concrete materials, with a view to the evaluation of time-series environmental deterioration. The structural failure in micro-structures was evaluated by a simple damage model and analyzed by the voxel finite element method. The application of the homogenization method enables us to evaluate the change over time in macroscopic elastic and diffusion properties. We also proposed a multi-scale analysis method for heat conduction problem of porous media based on the homogenization method. For the implementation of multi-scale heat conduction analysis, we discuss the differences and characteristics of the homogenization for heat conduction problem in comparison with that for deformation problem particularly by focusing our attention to the definition of micro-structure (unit cell). First, we formulated the homogenization method for heat conduction problem considering the heat transfer at porous boundaries in micro-scale and specify the points to notice of the formulation. Secondly, we examined the validity of the proposed method of multi-scale heat conduction analysis based on the homogenization method by carrying out simple several numerical experiments. Finally, a 3-dimensional numerical example for porous medium at elevated temperature is presented to demonstrate the capability of the method. The finite cover method (FCM) for quasi-brittle heterogeneous solids and the associated modeling method was developed. After introducing the FCM in conjunction with the mortar approximations for material interfaces, and attracting attention to the modeling of surfaces of strong discontinuities and material interfaces by means of spatially fixed regular mesh, we presented the associated modeling method for complex heterogeneous solids and discussed the issues in computational implementation especially for dealing with multiple cohesive crack growth in meso-scale heterogeneous media. Then, after carrying out simple performance studies, we demonstrated the promise and potential of the proposed method in several numerical examples. By performing numerical simulations of propagating cracks in concrete due to reinforcement corrosion, we illustrated various modes of crack paths according to the thickness of overburden for reinforcing steel, and investigated their underlying mechanisms. In order to accurately simulate the initiation and propagation of cracks, we enhanced the finite cover method (FCM) so as to working with regularly structured mesh without remeshing and characterized nonlinear behavior of process zone fracture by means of the cohesive crack model. The method enabled us to not only reproduce the modes of crack paths reported in experimental studies, but also predict the deterioration of concrete.
Earthquake Disaster Mitigation Strategy Based on Seismic Simulation of Mega-City

KIYONO Junji, HORI Muneo, TERADA Kenjiro, KARATANI Yuka, ONO Yusuke, FURUKAWA Aiko

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Kyoto University

2004 - 2006

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In the 1995 Kobe Earthquake, over 110 thousand houses were destroyed and more than 6,400 people died. Most of the people were killed by the collapse of existing low earthquake-resistant houses. However, evidences show that so many pre-code houses exist and the public awareness of potential losses during earthquakes is low. Better understanding on seismic behavior of the building is indispensable. One of the solutions is to encourage public awareness for strengthening of their own houses by letting them know how their town shakes during an earthquake and what happens in his/her house. In this research, we proposed the earthquake disaster mitigation strategy based on the seismic simulation of structures during an earthquake. As the amount of total buildings in a city is huge, statistic approaches are commonly employed. Therefore, results of estimation obtained are in average and might not be sufficient in convincing the public. On utilizing 3D GIS data, this study provides a method of constructing structural models of large amount of buildings, which enables seismic analysis of building structures. Evacuation behavior under emergency situation also can be simulated. To reduce the casualty due to earthquakes, it is very important to know the process structures collapse and how the occupants get injured. Three dimensional behavior of the collapse of timber frame houses under seismic motion were analyzed by using Distinct Element Method (Fig. 3). Outputs can be used as a useful tool of risk communication. These contents are open to the public and can be downloaded through web-site
国際フォーラム「土木工学における計算力学手法の新展開」の企画調査

樫山和男, 寺田賢二郎, 岡澤重信, 西村直志, 牛島省, 斉木功

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(C)

Institution: 中央大学

2004 - 2004

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本企画調査では、2005年8月に実施予定の国際フォーラム「土木工学における計算力学手法の新展開」に先立ち、最先端の計算力学の研究動向を調査するとともに、土木工学が抱える様々な問題点に対して、計算力学的なアプローチによる解決が可能な対象をピックアップし、「土木工学における計算力学の新しい展開」の方向性を提言するフォーラム実施に向けた具体的な準備活動を行った。本企画調査によって,以下の成果を得た. 1.土木工学において重要かつ緊急度の高い以下の8件の計算力学に関する課題(主に解析手法)を取り上げ、それらの内容及び動向に関する最新の調査を行った. 1)マルチスケール解析手法 2)マルチフィジックス解析手法 3)不連続性体の解析手法 4)境界要素法の高速化・効率化 5)自由・移動境界問題の解析手法 6)メッシュフリー解析手法 7)並列計算とハイパフォーマンスコンピューティング 8)都市のモデリング手法 2.上記の8項目に関する調査結果を披露する勉強会を2回実施した. 3.調査結果を整理してまとめ,約300ページに及ぶ報告書を作成した。 4.国際フォーラムの企画立案を行った(開催日:2005年8月26日-27日,場所:中央大学).また,3名の特別講演者の人選を行った.
Development of flaw evaluation system for large civil structures by using low frequency ultrasonic wave and scattered waveforms

YAMADA Masaki, KIMURA Tomonori, TERADA Kenjiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2001 - 2003

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The research about the technique of ultrasonic flaw reconstruction in elastic materials based on inverse scattering methods are carried out to develop a non-destructive evaluation system for large civil structures made by concrete materials. In this project, two and three dimensional elastodynamic inverse scattering methods are developed. The scattered wave measurement and the attenuation and phase velocity measurement were carried out for utilization of measured wave data. And, the comparison of reconstructed shapes by Born and Kirchhoff inverse scattering methods brought flaw characterization system. The shape reconstruction of flaws in the concrete materials by Born and Kirchhoff inverse scattering method is investigated. In this method, the angular and frequency diversities of the scattered waves are superposed in the form of the Fourier transform in the polar coordinate. An efficient method to accelerate the inversion process is proposed by rearranging the scattered wave data from the polar coordinate to the rectangular coordinate. The concrete specimens, that contain flaw models and has flat surface, are prepared and the scattered waveforms are acquired from the pulse-echo measurement. The performance of the shape reconstructions is shown for flaw models is the prepared specimens. As the result, the possibility of this method to reconstruct the shape of flow in concrete materials is shown.
材料と構造を結ぶマルチスケール解析手法に関する研究

寺田賢二郎

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 奨励研究(A)

Institution: 東北大学

1999 - 2000

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本研究の根幹に位置する均質化法は、設計物としての解析対象をマクロ構造物として、その物性を材料ミクロ領域で観察される構造の解析から得られる応答を得るための数学理論である。申請者は、この均質化理論を用いて非均質材料のマクロ的な等価物性を陽に求めずに「材料」と「構造」の2つの異なるスケール間の連成問題を解析するという全く新しいタイプの非線形マルチスケール解析技術を開発した。前年度は、対象を「弾塑性体からなる複合材料」に限定して、全体(マクロ)構造の材料応答をミクロスケールの弾塑性体としたときの解析そのものと置き換える一般的な数値解析アルゴリズムを提示した。これを受けて、本年度はこの解析法を他種非均質材料に拡張した。具体的には、(1)有限変形を伴う樹脂複合材料、(2)ミクロ的に離散体と見なされる材料についてのマルチスケール解析法について、定式化と解析プログラムを開発し、その適用性を検討した。特に(1)では、一般的な有限ひずみ問題の定式化から出発して幾何学的非線形性までも組み込んだマルチスケールモデリングを世界で初めて実現し、多くの数値解析例によって実用的なソフトウェアとしての実装の可能性を示唆した。また(2)では、ミクロ的に離散体ではあるがマクロ的には連続体と見なされる材料の代表格として地盤材料を想定して、幾つかの解析例を示し、手法としての汎用性を強調した。中でも、3軸試験シミュレーションは、マクロ構造の複雑な構成則を持ち込まなくても、地盤としての弾塑性材料挙動が再現できることを示した。
Manifold Finite Element Method And its Application for Naval Structural Analysis.

OHTSUBO Hideomi, TERADA Keziroh, SUZUKI Katsuyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: THE UNIVERSITY OF TOKYO

1997 - 1999

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The characteristic idea of the Finite Cover Method and Manifold Method is to define the mathematical field for approximation independent from the physical field, where the partial differential equation is required to be satisfied. The approximation is constructed ton the mathematical field by some distributed covers. Since the mathematical field is defined irrelevant with the geometrical shape of the physical field, any complex structure can be covered simply by mathematical covers with regular shapes. The voxel data is employed for cover distribution by using square or cubic covers so that the merit of voxel analysis can be inherited to improve the efficiency of solid structural analysis. The problem of linear independence is discussed for Finite Cover Method and some mathematical conditions for linear independence are proposed. The technique of "Shape Voxel" is proposed for integration of stiffness matrix and evaluation of boundary conditions in 3D solid analysis. Numeric examples show that since the model generation using voxel information is very simple, the total analysis becomes more effective. The Finite Cover Method is then applied for large deformation problem, and the re-mesh burden is reduced obviously due to the simple cover distribution. A structural analysis system is developed with the Finite Cover Method, which can process automatically after inputting CAD data. The proposed method can surmount difficulties of model generation in complex 3D solid analysis.

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ゴム材料のマルチスケールCAEシステムの開発

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ゴム材料の微視的構造を考慮してその巨視的力学特性を把握するための数値最良試験の実施方法の開発とシステム化
ブレーキ鳴き現象におけるアセンブリ部材接合部の微視的力学挙動の影響評価

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ブレーキアセンブリーの接合部における表面の凹凸（アスペリティ）の数値モデルに対して数値実験を行い、その非線形・非弾性変形挙動を特徴付けることによりブレーキ鳴きのメカニズムを解明する。
均質化法を用いた多孔質セラミックス材料の特性評価法

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多孔質セラミックス材料を奮迅フィルターに用いる事を前提に、その微視的幾何性状が巨視的透過特性とフィルター性能に及ぼす影響を調査する。
大規模積層体における均質化数値解析技術の開発

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1方向周期性を有する大規模積層構造物に対して，均質化理論を拡張した理論を構築し，対応する数値解析技術を開発する．具体的には，燃料電池のセルスタック構造を対象として，精度検証を行うとともに，手法の有効性を確認する．
トポロジー最適設計に関する研究

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任意の追加の制約パラメータを導入することなく、チェッカーボードフリートポロジー最適化手法を提案する。この目的は、固定設計領域における連続物質分配のための有限要素近似を導入することによって達成される。
ミクロ組織がマクロ材料特性の異方性に及ぼす影響に関する研究

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塑性加工時のミクロ組織形態の変化とそのマクロ機械特性の異方性に及ぼす影響に関する研究
鋼の製造プロセスにおけるミクロ組織の制御手法に関する研究

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鉄鋼の製造プロセスにおける微視的構造の経時変化を考慮した、マクロ物性評価。
微視的構造特性に起因するブレーキ鳴きメカニズムに関する基礎的検討

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ブレーキ表面の凹凸（アスペリティ）の数値モデルに対して数値実験を行い、その非線形・非弾性変形挙動を特徴付けることによりブレーキ鳴きのメカニズムを解明する。
有限(大)変形を伴う柔軟構造物のトポロジー最適設計法の開発

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位相（トポロジー）最適設計手法を有限変形固体にまで拡張して、柔軟構造物の設計へと適用する研究
鋼のマクロ材料特性に対するミクロ組織の影響に関する研究

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主に炭素鋼を対象として、その微視的構造に対して均質化法を適用し、その幾何学的特性が巨視的降伏強度に与える影響について調査する。
地盤解析における有限要素法の誤差評価と精度向上手法の開発

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原子力発電所の建屋の基礎となる地盤の解析を想定して、その数値解析精度に対する有限要素メッシュと要素の性能の影響を調査する。
イメージベース均質化法解析を用いた血液フィルターの設計

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多孔質体に対して均質化法を適用することで得られる等価物性、すなわち浸透係数を血液フィルターの設計に応用するための研究

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