研究者詳細

顔写真

オオツカ　ケイスケ
大塚　啓介
Keisuke Otsuka
所属
大学院工学研究科　航空宇宙工学専攻　宇宙システム講座（宇宙構造物工学分野）
職名
准教授
学位

  • 博士（工学）（東北大学）

  • 修士（工学）（東北大学）

e-Rad 研究者番号
20881189
プロフィール

次世代航空宇宙システムに代表される大変形構造のシミュレーション方法の開発を行っています．特に，大変形有限要素法の１種である絶対節点座標法Absolute Nodal Coordinate Formulation (ANCF)を中心としたマルチボディシミュレーション，流体構造連成シミュレーションに取り組んでいます．ANCFの詳細はこちらのオープンアクセス文献をご覧ください．

https://doi.org/10.1115/1.4054113

経歴 6

  • 2023年4月 ～ 継続中
    東北大学　航空宇宙工学専攻　准教授

  • 2024年1月 ～ 2024年11月
    The University of Iowa (US)　Visiting Scholar

  • 2020年4月 ～ 2023年3月
    東北大学　航空宇宙工学専攻　助教

  • 2019年6月 ～ 2019年9月
    Imperial College London (UK)　Visiting Research Student

  • 2017年4月 ～ 2019年3月
    日本学術振興会　特別研究員DC2

  • 2014年8月 ～ 2015年6月
    KTH Royal Institute of Technology (Sweden)　Exchange Student

︎全件表示 ︎最初の5件までを表示

学歴 3

  • 東北大学　大学院工学研究科　航空宇宙工学専攻 博士課程

    2016年4月 ～ 2020年3月

  • 東北大学　大学院工学研究科　航空宇宙工学専攻 修士課程

    2014年4月 ～ 2016年3月

  • 東北大学　工学部　機械知能・航空工学科

    2010年4月 ～ 2014年3月

委員歴 7

  • 12th Asian Conference on Multibody Dynamics (ACMD2026) Scientific Committee

    2024年12月 ～ 継続中

  • 35th International Symposium on Space Technology and Science (ISTS2025) Program Organizer　Session Organizer

    2024年11月 ～ 継続中

  • 21st International Conference on Flow Dynamics (ICFD2024)　Session Organizer

    2024年1月 ～ 2024年11月

  • 20th International Conference on Flow Dynamics (ICFD2023)　Session Organizer

    2023年1月 ～ 2023年11月

  • 34th International Symposium on Space Technology and Science (ISTS2023) Program Organizer

    2022年11月 ～ 2023年6月

  • 第34回「電磁力関連のダイナミクス」シンポジウム　実行委員

    2021年12月 ～ 2022年5月

  • 14th International Conference on Flow Dynamics (ICFD2017)　Session Organizer

    2017年5月 ～ 2017年10月

︎全件表示 ︎最初の5件までを表示

所属学協会 4

  • American Society of Mechanical Engineers (ASME)

  • American Institute of Aeronautics and Astronautics (AIAA)

  • 日本航空宇宙学会

  • 日本機械学会

研究キーワード 11

  • 惑星探査航空機

  • 火星飛行機

  • AI

  • ディープラーニング

  • 機械学習

  • 成層圏プラットフォーム

  • トポロジー最適化

  • 風洞実験

  • 空力弾性

  • 浮体式洋上風車

  • マルチボディダイナミクス

研究分野 1

  • フロンティア（航空・船舶） / 航空宇宙工学 /

受賞 15

  1. Best Presentation Award for Young Researchers

    2023年11月　20th International Conference on Flow Dynamics (ICFD2023)　"Simulation Framework for Wake-Induced Aeroelastic Phenomena"

  2. インテリジェント・コスモス奨励賞

    2023年5月　公益財団法人 インテリジェント・コスモス学術振興財団　「超柔軟浮体式洋上風車の実現に向けた歪モデリング法の構築」

  3. 交通・物流部門大会 部門大会賞

    2023年3月　日本機械学会　「航空機・車両・鉄道・エレベータに対する統一的な柔軟マルチボディ解析法の構築」

  4. Best Poster Presentation Award

    2022年11月　The 22ned International Symposium on Advanced Fluid Information (AFI-2022)　"Geometrically Nonlinear Beam Model for Slender Multibody Wings"

  5. 研究開発奨励賞

    2022年11月　エヌエフ基金　「超柔軟浮体式洋上風車の実現に向けた流体構造連成解析法の構築」

  6. 日本機械学会奨励賞（研究）

    2022年4月　日本機械学会　「展開翼航空機のマルチフィデリティ解析法の構築と実験実証の研究」

  7. 青葉工学研究奨励賞

    2021年12月　青葉工学振興会　「次世代航空機の高効率な一連解析を実現する非線形移動型モデリング」

  8. 井上研究奨励賞

    2021年2月　井上科学振興財団　「展開翼航空機の柔軟マルチボディ解析に関する研究」

  9. Best Presentation Award for Young Researchers

    2020年12月　17th International Conference on Flow Dynamics (ICFD2020)　"Flexible Wing Fluid-Structure Interaction Model Coupling Unsteady Vortex Lattice Method and Absolute Nodal Coordinate Formulation"

  10. オーディエンス表彰

    2019年8月　日本機械学会 Dynamics and Design Conference 2018　「展開型モーフィング翼の柔軟マルチボディシミュレーション」

  11. 若手奨励賞

    2018年8月　日本航空宇宙学会 第60回構造強度に関する講演会　「全体座標表現に基づく柔軟展開翼の３次元マルチボディ解析法の開発」

  12. Best Presentation Award for Students Session

    2016年10月　13th International Conference on Flow Dynamics (ICFD2016)　"Deployment Simulation of Morphing Wing"

  13. 独創研究学生賞

    2016年3月　日本機械学会東北支部 第51期総会・講演会　「非定常空気力を受けるモーフィング翼のMBDシミュレーション」

  14. グローバル萩海外留学奨励賞

    2014年7月　東北大学　「スウェーデン王立工科大学KTH交換留学」

  15. 学生賞

    2014年2月　日本航空宇宙学会

︎全件表示 ︎最初の5件までを表示

論文 47

  1. Data-Driven Real-Time Topology Optimization Using Consistent Rotation-Based Moving Morphable Components 国際誌 査読有り

    Hirotani, S., Yaji, K., Makihara, K., Otsuka, K.

    AIAA Journal　(in press)　2025年12月

    出版者・発行元： AIAA

  2. Deep Learning for Constructing Ordinary Differential Equations in Hamiltonian Formulation of Multibody Systems 国際誌 査読有り

    Dong, S., Kuzuno, R., Makihara, K., Otsuka, K.

    Mechanics Research Communications　(in press)　2025年10月

    出版者・発行元： Elsevier

  3. Nonlinear Dynamic Analysis Framework for Slender Structures Using the Modal Rotation Method 国際誌 査読有り

    Shizuno, Y, Dong, S, Kuzuno, R, Okada, T, Kawashima, S, Makihara, K, Otsuka, K

    ASME Journal of Computational and Nonlinear Dynamics　20　(2)　021002　2025年3月

    出版者・発行元： ASME

    DOI： 10.1115/1.4067201 　

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    Owing to their low induced drag, high-aspect-ratio wings are often applied to aircraft, particularly high-altitude long-endurance (HALE) aircraft. An analytical method that considers geometrical nonlinearity is necessary for the analysis of high-aspect-ratio wings as they tend to undergo large deformations. Nonlinear shell/plate or solid finite element methods are widely used for the static analysis of wing strength. However, an increase in the number of elements drastically increases the computational costs owing to the complexity of wing shapes. The modal rotation method (MRM) can avoid this additional expense by analyzing large deformations based on modes and stiffness matrices obtained from any linear or linearized model. However, MRM has only been formulated as a static analysis method. In this study, a novel modal-based dynamic analysis framework, referred to as dynamic MRM (DMRM), is developed to analyze slender cantilever structures. This paper proposes a method to discretize dynamics by capitalizing on the fact that MRM considers geometrical nonlinearity based on deformed shapes. The proposed method targets slender structures with small strains and large displacements and considers geometrical nonlinearity, but not material nonlinearity. Additionally, a formulation method for the work performed by a follower force is proposed. The energy stored in the structure agreed with the work performed by an external force in each performed simulation. DMRM achieved a 95% reduction in the calculation time compared with a nonlinear plate finite element method in a performed simulation.

  4. Moving Morphable Components Using Strain-Based Beam Geometry Description for Topology Optimization 国際誌 国際共著 査読有り

    Otsuka, K, Yamashita, H, Sugiyama, H, Dong, S, Kuzuno, R, Makihara, K

    AIAA Journal　62　(12)　4846-4854　2024年12月

    出版者・発行元： AIAA

    DOI： 10.2514/1.J064272 　

  5. Piezoelectric Flutter Energy Harvesting: Absolute Nodal Coordinate Formulation Model and Wind Tunnel Experiment 国際誌 国際共著 査読有り

    Mukogawa T., Shimura, K., Dong, S., Fujita, K., Nagai, H., Kameyama, M., Shi, Y., Jia, Y., Soutis, C., Kurita, H., Narita, F., Hara, Y., Makihara, K., Otsuka, K.

    Mechanics Research Communications　143　104351　2024年11月

    出版者・発行元： Elsevier BV

    DOI： 10.1016/j.mechrescom.2024.104351 　

    ISSN：0093-6413

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    This study proposes a new flutter harvesting analysis framework based on an absolute nodal coordinate formulation (ANCF) model that includes a nonlinear finite element method, a three-dimensional unsteady vortex lattice method that considers nonlinearities, and a piezoelectric equation. Because conventional studies assumed no extensionality of the neutral axis, use of flutter harvester configurations was restricted. However, this framework using the ANCF model can be applied to different configurations (e.g., extensible harvesters with fixed-fixed boundaries or multibody harvesters). The feasibility of the proposed method was verified by conducting wind tunnel experiments. The frequencies, root mean square (RMS) displacements, and RMS voltages of the analysis and experiment were compared. The difference between experiment and analysis was 23% in terms of frequencies. One of the reasons for the difference was viscous drag. Although the results were not a perfect match, the introduction of a viscous drag model will be considered in future studies to enhance this framework.

  6. Moving Morphable Multi Components Introducing Intent of Designer in Topology Optimization 国際誌 国際共著 査読有り

    Otsuka, K, Dong, S, Kuzuno, R, Sugiyama, H, Makihara, K

    AIAA Journal　61　(4)　1720-1734　2023年4月

    出版者・発行元： AIAA

    DOI： 10.2514/1.J062210 　

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    Topology optimization based on moving morphable components efficiently generates a topology that is expressed by a few geometrical design variables. However, conventional moving morphable components have three problems: lack of C1 continuity between components, difficulty in describing a smooth rollup shape, and difficulty in generating a rigid joint to an optimized topology. In this study, a novel topology optimization framework was developed by introducing theories devised for multibody analysis. First, an adaptive moving morphable component based on absolute nodal coordinate formulation was proposed. Because both the position and gradient are used as design variables, C1 continuity is ensured. Second, a position and gradient connection algorithm leveraging the linear constraint of the absolute nodal coordinate formulation was proposed to describe the smooth rollup shape. Third, a rigid joint was generated by introducing the gradient constraint equation in an optimizer. The developed framework exhibited superior convergence as compared with the conventional one in the benchmark short beam problem. It successfully generated an optimal topology with the intent of a designer (that is, designer-selected topology continuity and rigid joints), which facilitated the assembly and manufacturing of topologically optimized structural members to construct an entire aerospace structure.

  7. Joint Parameters for Strain-Based Geometrically Nonlinear Beam Formulation: Multibody Analysis and Experiment 国際誌 査読有り

    Otsuka, K, Dong, S, Fujita, K, Nagai, H, Makihara, K

    Journal of Sound and Vibration　538　(117241)　2022年11月

    DOI： 10.1016/j.jsv.2022.117241 　

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    A novel singularity-free, tuning-free, and reduced-order strain-based beam formulation is developed for analyzing slender multibody systems such as folding wing aircraft and offshore wind turbines that perform large rigid body motions and geometrically nonlinear deformations. Conventional linear deformation models are not suitable for the analysis, whereas the strain-based beam formulation has a potential to describe the geometrically nonlinear deformation efficiently using a small number of strain variables and a constant stiffness matrix obtained from a recursive equation. However, it suffers from singularity, penalty-coefficient tuning, and many variables when applied to multibody systems. This study addressed these problems by proposing joint parameters. Singularity-free joint parameters introduced in the recursive equation produce a novel velocity transformation that removes coefficient tuning and achieves model reduction. We demonstrate that the proposed method can perform a more stable multibody analy is compared to that using the conventional method. Further, we measured the strain of the folding wing during deployment in a wind tunnel at the Institute of Fluid Science, Tohoku University to validate the strain-based beam formulation with the proposed joint parameters. The strain of the proposed method is in good agreement with that of the wind tunnel experiment, wherein the folding wing performed multibody dynamic motion with geometrically nonlinear deformation.

  8. Consistent Strain-Based Multifidelity Modeling for Geometrically Nonlinear Beam Structures 国際誌 国際共著 査読有り

    Otsuka, K, Wang, Y, Fujita, K, Nagai, H, Makihara, K

    ASME Journal of Computational and Nonlinear Dynamics　17　(11)　111003　2022年11月

    DOI： 10.1115/1.4055310 　

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    Conventional multifidelity modeling for slender structures such as folding-wing aircrafts and offshore wind turbines does not allow the generation of multiple fidelity models that consistently use the same external force model, which complicates simulation program and design process. Although consistent absolute nodal coordinate formulation (ANCF)-based multifidelity modeling was recently proposed to address this inconsistency, it still has the following four problems: (1) a large number of generalized coordinates, (2) a large number of Lagrange multipliers, (3) difficulty in constraining high-frequency axial deformation, and (4) a lack of lower-fidelity models. The lower-fidelity models that have not yet been developed are torsion-only beam, extension-only truss, and bending-only beam models. The objective of this study was to develop a novel consistent strain-based multifidelity modeling framework that addresses these problems by leveraging new vector-strain transformations from ANCF to the strain-based beam formulation. We employed a hydrodynamic force model based on Morison's equation as an example to demonstrate all fidelity models obtained from the proposed strain-based framework consistently use the same external force model. We conducted five simulations to verify the proposed models. The consistent external force model for the hydrodynamic force was then validated by comparison with experimental data. The simulation results concurred with those of conventional models and experiments. Low-fidelity models exhibited over 98% reduction in calculation time compared to high-fidelity models, which helps in conceptual and initial designs that require a large number of parametric simulations.

  9. Strain-Based Geometrically Nonlinear Beam Formulation for Rigid-Flexible Multibody Dynamic Analysis 国際誌 国際共著 査読有り

    Otsuka, K, Wang, Y, Palacios, R, Makihara, K

    AIAA Journal　60　(8)　49-4968　2022年8月

    DOI： 10.2514/1.J061516 　

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    Geometrically nonlinear strain-based beam formulation has the potential to analyze flexible slender components in multibody systems efficiently owing to the minimum number of variables and constant stiffness matrix. The objective of this study is to develop a multibody dynamic analysis framework based on the strain-based beam formulation. To this end, we describe the constraint equation using the vector variables of the absolute nodal coordinate formulation that exhibits a velocity-transformation relationship with the strain-based formulation. Subsequently, we divide the Jacobian of the constraint equation into two terms. One term is equivalent to the velocity transformation matrix that is currently implemented in the existing strain-based analysis framework. The other term is a simple constant or linear Jacobian defined based on the orthonormal vectors of the absolute nodal coordinate formulation. This simple Jacobian description integrates the strain-based beam formulation with multibody dynamic theories to handle open- and closed-loop joints. The obtained numerical results validate that the proposed strain-based multibody dynamic analysis method concurs well with and exhibits a better convergence than the conventional flexible multibody dynamic analysis method.

  10. Recent Advances in the Absolute Nodal Coordinate Formulation: Literature Review from 2012 to 2020 国際誌 国際共著 査読有り

    Otsuka, K, Makihara, K, Sugiyama, H

    ASME Journal of Computational and Nonlinear Dynamics　17　(8)　080803　2022年8月

    DOI： 10.1115/1.4054113 　

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    Absolute nodal coordinate formulation (ANCF) is a non-incremental nonlinear finite element procedure that has been successfully applied to the large deformation analysis of multibody systems for more than two decades. Although a comprehensive review on ANCF was conducted by Gerstmayr, et al. in 2013, significant theoretical developments have been made since then at a much faster pace to improve the element accuracy and computational efficiency. In order to overview recent advances in ANCF simulation capabilities that are not covered in the first review paper, this paper aims to conduct a comprehensive review of 259 papers concerning ANCF published from 2012 through 2020. It is shown that the ANCF element library has grown substantially for beam, plate/shell, solid elements, eliminating drawbacks of ANCF elements developed earlier. The application areas have extended, especially in the aerospace field, and the enhanced ANCF simulation capabilities have been demonstrated in solving challenging engineering problems. Research efforts have been made continually to integrate computer-aided design (CAD) and analysis with ANCF elements. Furthermore, computational improvements and multiphysics simulations have become major research topics for ANCF. It is also demonstrated that the accurate ANCF geometry description can be exploited to facilitate structural optimization of multibody systems.

  11. Aeroelastic Simulation of High-Aspect Ratio Wings with Intermittent Leading-Edge Separation 国際誌 国際共著 査読有り

    Wang, Y., Zhao, X., Palacios, R., Otsuka, K.

    AIAA Journal　60　(3)　1769-1782　2022年3月

    DOI： 10.2514/1.J060909 　

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    We present a medium-fidelity aeroelastic framework for computing intermittently separating three-dimensional (3-D) flows around high-aspect ratio wings with a significantly reduced computational cost compared to the computational-fluid- dynamics-based method. To achieve that, we propose a modified three-dimensional vortex panel method with leading-edge separation controlled by leading-edge suction parameter theory, and its incorporation in a coupled aeroelastic solver for the dynamic response of these systems. Numerical verifications and simulations are presented on both attached and separated aeroelastic test cases, demonstrating the method on postflutter limit-cycle oscillation of a cantilever wing, and leading-edge separation on a deploying wing, a complex kinematic response. In both cases we were able to capture three-dimensional interactions on intermittently separating dynamic flowfields using a low computational cost.

  12. Nonlinear Aeroelastic Analysis of High-Aspect-Ratio Wings with a Low-Order Propeller Model 国際誌 国際共著 査読有り

    Otsuka, K., Del Carre, A., Palacios, R.

    AIAA Journal of Aircraft　59　(2)　293-306　2022年3月

    DOI： 10.2514/1.C036285 　

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    A nonlinear aeroelastic analysis framework for high-aspect-ratio wings that includes the aerodynamic effects of propellers is described. The high computational cost required for modeling aerodynamic interaction between the wing and propeller wake is reduced by taking advantage of the relatively slow dynamics of the wing. Consequently, the propeller wake is modeled as a straight vortex cylinder that does not require a computationally expensive wake updating process. By leveraging the smallness of the propeller, an averaged vortex cylinder method is proposed that calculates the induced velocities of the propeller vortex cylinder efficiently without suffering from a numerical singularity and loss of accuracy. The induced velocities are considered in the wing aerodynamic force calculation using an unsteady vortex lattice method. An efficient propeller cylinder coordinate generation method modeling the propeller-attached wing by absolute nodal coordinate formulation with a multibody dynamic theory is also proposed. The developed framework is validated by comparison with other formulations. A static aeroelastic analysis on a low-speed high-aspect-ratio wing demonstrates that the propeller-induced axial velocity causes the deflection change of 5.4%. A nonlinear dynamic result shows that the propeller decreases the vibration amplitude by 6.7% because the propeller-induced axial velocity enhances the aerodynamic damping.

  13. Three-Dimensional Aeroelastic Model for Successive Analyses of High-Aspect-Ratio Wings 国際誌 国際共著 査読有り

    Otsuka, K., Wang, Y., Makihara, K.

    ASME Journal of Vibration and Acoustics　143　(6)　061006　2021年12月

    出版者・発行元：

    DOI： 10.1115/1.4050276 　

    ISSN：1048-9002

    eISSN：1528-8927

    詳細を見る 詳細を閉じる

    Next-generation civil aircraft and atmospheric satellites will have high-aspect-ratio wings. Such a design necessitates successive analysis of static, frequency, and time-domain dynamic responses based on a three-dimensional nonlinear beam model. In this study, a new successive-analysis framework based on an absolute nodal coordinate formulation with mean artificial strains (ANCF-MAS) is developed. While retaining the advantages of other 3D ANCF approaches, such as constancy of the mass matrix and absence of velocity-dependent terms, ANCF-MAS uses the elastic force of the mean artificial strains to remove cross-sectional deformations that cause locking problems. The equation becomes a differential equation with an easily linearized elastic force that enables not only static and dynamic analyses but also frequency analysis using standard eigenvalue solvers. The solutions converge to the analytical frequencies without suffering from locking problems. A proposed successive-analysis method with model-order reduction reveals that the frequencies vary with the nonlinear static deformation because of the 3D deformation coupling. This reduced-order model agrees well with nonlinear models even when the wing experiences a large nonlinear dynamic deformation.

  14. Absolute Nodal Coordinate Formulation with Vector-Strain Transformation for High Aspect Ratio Wings 国際誌 国際共著 査読有り

    Otsuka, K., Wang, Y., Makihara, K.

    ASME Journal of Computational and Nonlinear Dynamics　16　(1)　011007　2021年2月

    DOI： 10.1115/1.4049028 　

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    High aspect ratio wings are potential candidates for use in atmospheric satellites and civil aircraft as they exhibit a low induced drag, which can reduce the fuel consumption. Owing to their slender and light weight configuration, such wings undergo highly flexible aeroelastic static and dynamic deformations that cannot be analyzed using conventional linear analysis methods. An aeroelastic analysis framework based on the absolute nodal coordinate formulation (ANCF) can be used to analyze the static and dynamic deformations of high aspect ratio wings. However, owing to the highly nonlinear elastic force, the statically deformed wing shape during steady flight cannot be efficiently obtained via static analyses. Therefore, an ANCF with a vector-strain transformation (ANCF-VST) was proposed in this work. Considering the slender geometry of high aspect ratio wings, the nodal vectors of an ANCF beam element were transformed to the strains. In this manner, a constant stiffness matrix and reduced degrees of freedom could be generated while capturing the highly flexible deformations accurately. The ANCF-VST exhibited superior convergence performance and accuracy compared to those of analytical approaches and other nonlinear beam formulations. Moreover, an aeroelastic analysis flow coupling the ANCF-VST and an aerodynamic model based on the unsteady vortex lattice method was proposed to perform the static and dynamic analyses successively. The proposed and existing aeroelastic frameworks exhibited a good agreement in the analyses, which demonstrated the feasibility of employing the proposed framework to analyze high aspect ratio wings.

  15. Versatile Absolute Nodal Coordinate Formulation Model for Dynamic Folding Wing Deployment and Flutter Analyses 国際誌 国際共著 査読有り

    Otsuka, K., Wang, Y., Makihara, K.

    ASME Journal of Vibration and Acoustics　141　(1)　011014　2019年2月1日

    DOI： 10.1115/1.4041022 　

    ISSN：1048-9002

    eISSN：1528-8927

  16. Multifidelity Modeling of Deployable Wings: Multibody Dynamic Simulation and Wind Tunnel Experiment 国際誌 国際共著 査読有り

    Otsuka, K., Wang, Y., Fujita, K., Nagai, H., Makihara, K.

    AIAA Journal　57　(10)　4300-4311　2019年

    DOI： 10.2514/1.J058676 　

    ISSN：0001-1452

  17. Absolute Nodal Coordinate Beam Element for Modeling Flexible and Deployable Aerospace Structures 国際誌 査読有り

    Otsuka, K., Makihara, K.

    AIAA Journal　57　(3)　1343-1346　2019年

    DOI： 10.2514/1.J057780 　

    ISSN：0001-1452

  18. Deployment Simulation Using Absolute Nodal Coordinate Plate Element for Next-Generation Aerospace Structures 国際誌 査読有り

    Otsuka, K., Makihara, K.

    AIAA Journal　56　(3)　1266-1276　2018年

    DOI： 10.2514/1.J056477 　

    ISSN：0001-1452

  19. Deployable Wing Model Considering Structural Flexibility and Aerodynamic Unsteadiness for Deployment System Design 国際誌 国際共著 査読有り

    Otsuka, K., Wang, Y., Makihara, K.

    Journal of Sound and Vibration　408　105-122　2017年11月10日

    DOI： 10.1016/j.jsv.2017.07.012 　

    ISSN：0022-460X

    eISSN：1095-8568

  20. Aeroelastic Deployable Wing Simulation Considering Rotation Hinge Joint Based on Flexible Multibody Dynamics 国際誌 査読有り

    Otsuka, K., Makihara, K.

    Journal of Sound and Vibration　369　147-167　2016年5月12日

    DOI： 10.1016/j.jsv.2016.01.026 　

    ISSN：0022-460X

    eISSN：1095-8568

  21. Parametric Studies for the Aeroelastic Analysis of Multibody Wings 国際誌 査読有り

    Otsuka, K., Makihara, K.

    Transactions of JSASS, Aerospace Technology Japan　14　(ists30)　Pc_33-Pc_42　2016年

    出版者・発行元： 一般社団法人 日本航空宇宙学会

    DOI： 10.2322/tastj.14.Pc_33 　

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    Air density on Mars is much lower than that on Earth. To generate sufficient lifting force to fly, Mars-airplanes need to have a larger wing area than Earth-airplanes. The recently developed Mars-airplanes have multibody wings that can be folded and deployed to realize larger wing area and compactness. Aeroelastic analyses of the wings are necessary to avoid catastrophic behaviors, such as flutter or divergence. However, conventional aeroelastic analysis methods cannot be applied to the multibody wing because these wings have mechanical joints for connecting wing bodies, and thus, they differ significantly from conventional wings. In this paper, a new analysis method that can be applied to the multibody wing is explained. The method combines aerodynamics, multibody dynamics theory, and absolute nodal coordinate formulation. By using this method, we simulate the aeroelastic motion of multibody wings. We investigate the changes in aeroelastic motion when we change the number of the wing bodies and the structural parameters.

  22. Reduced-Order Modeling of Hamiltonian Formulation in Flexible Multibody Dynamics: Theory and Simulations 国際誌 査読有り

    Dong, S., Kuzuno, R., Otsuka,K., Makihara,K.

    Applied Mathematical Modelling　114　116055　2025年8月

    出版者・発行元： Elsevier

    DOI： 10.1016/j.apm.2025.116055 　

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    Flexible multibody dynamics has been developed as an effective method for analyzing mechanical structures, wherein the Hamiltonian formulation draws attention for advantages such as the systematic handling of systems with varying mass. However, the utilization of the finite element method typically results in a large number of variables, which deteriorates computational efficiency. An effective method to reduce the number of variables (coordinates and canonical conjugate momentum) in Hamiltonian formulation needs to be presented. This paper proposes a novel reduced-order modeling of the Hamiltonian formulation based on the component mode synthesis method. A novel definition of momentum is proposed to construct the equation of motion. Compared with conventional Hamiltonian formulations, not only generalized coordinates but also momentum is reduced. By combining the absolute nodal coordinate formulation with the proposed formulation, it is applicable to analyze nonlinear structures with large deformation and rotations. Four numerical simulations were conducted to evaluate the performance of the proposed formulation, and calculation time reductions of 52.1 %, 83.6 %, 93.4 %, and 81.5 % were achieved. Overall, the proposed Hamiltonian formulation exhibits high calculation efficiency, good numerical stability, and high accuracy.

  23. Support Vector Machine Framework for Detecting Ambiguous Contours of Space Debris Cloud 国際誌 査読有り

    Morimoto, D, Takahashi, H, Sugiyama, Y, Otsuka, K, Ohtani, K, Hasegawa, S, Makihara, K

    AIAA Journal of Spacecraft and Rockets　(in press)　2025年1月

    出版者・発行元： AIAA

  24. Statistically-Oriented Optimal Control and Disturbance Prediction for Piezoelectric Semi-Active Vibration Suppression 国際誌 査読有り

    Abe, M, Mishima, K, Hara, Y, Otsuka, K, Makihara, K

    IEEE Transactions on Control Systems Technology　(in press)　2025年1月

    出版者・発行元： IEEE

  25. System Identification of Multi-Degree-of-Freedom Structures Subject to Unmeasurable Periodic Disturbances Using a Piezoelectric Device 国際誌 査読有り

    Tang, T, Hara, Y, Meng, Z, Otsuka, K, Makihara, K

    Journal of Evolving Space Activities　(in press)　2025年1月

  26. Semi-Active Structural Excitation Method to Realize Energy-Saving On-Orbit Identification 国際誌 査読有り

    Hara, Y, Tang, T, Otsuka, K, Makihara, K

    Journal of Evolving Space Activities　2　125　2024年12月

    出版者・発行元： JSASS

    DOI： 10.57350/jesa.125 　

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    On-orbit identification has more stringent technical constraints than on-ground identification due to the operational environment. In particular, the amount of energy consumption is severely limited. This study proposes a novel identification method that does not consume a lot of energy and does not use input sequence information. The proposed method adopts piezoelectric semi-active control to excite a structural vibration and a covariance-driven stochastic subspace identification (SSI-COV) method. The piezoelectric semiactive control temporarily converts mechanical energy into electrical energy and then excites structural vibration using the temporarily converted electrical energy. Therefore, this is an energy-saving excitation method. Since the SSI-COV method identifies the structural model under the assumption that the input sequence is white noise, it identifies the structural model without any input information. We proposed a semi-active input generation method such that the properties of the semi-active input will be equivalent to those of the white noise. We validated the proposed method through numerical simulations and experiments. To explore the feasibility of the proposed method, this study employs a simple two-degree-of-freedom structure instead of a complex continuum structure. The proposed method identified the modal parameters of the structure and consumed only 68 mJ.

  27. High-Fidelity Flexible Multibody Model Considering Torsional Deformation for Nonequatorial Space Elevator 国際誌 査読有り

    Kuzuno, R, Dong, S, Takahashi, Y, Okada, T, Xue, C, Otsuka, K, Makihara, K

    Acta Astronautica　220　504-515　2024年7月

    出版者・発行元： Elsevier

    DOI： 10.1016/j.actaastro.2024.05.008 　

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    Space elevators are a promising technology for future space transportation. The primary component of a space elevator is a tether deployed from a geostationary orbit towards the Earth and into deep space. Payloads can be transported using a climber moving along the tether. However, obtaining a deeper comprehension of the precise dynamics of a space elevator is challenging. The tether could have various deformations such as elongation, bending, and torsion owing to its flexible nature and the low level of vibration damping in space. Therefore, understanding those effects on the tether is essential for the design concept of a space elevator. Reproducing the behavior of space tether systems on the ground is challenging, which is primarily due to the scale of the system and the difficulty of accurately replicating a space environment. Thus, high-fidelity numerical analysis methods are required to analyze the dynamic response of space elevators precisely. Previously proposed analysis models of space tether systems with climbers have focused on elongation, bending, and rigid body motion of the tether, and the effect of torsional deformation has been neglected. However, a tether can be twisted easily owing to its low torsional stiffness. This study established high-fidelity numerical simulation models for space elevators considering large deformations including the torsion of a tether. This study developed a flexible multibody model with a moving climber using the absolute nodal coordinate formulation with 14 degrees of freedom. Further, the gravitational perturbation caused by the non-sphericity of the Earth was considered. Using the constructed model, the motion and deformation of nonequatorial space elevators caused by the climber motion and the disturbance in the space environment were investigated. The obtained results indicate that gravitational perturbation can induce torsional deformation, particularly at higher anchor latitudes.

  28. State Observer of Multibody Systems Formulated Using Differential Algebraic Equations 国際誌 査読有り

    Okada, T, Dong, S, Kuzuno, R, Takahashi, Y, Shizuno, Y, Hara, Y, Otsuka, K, Makihara, K

    Multibody System Dynamics　61　(2)　2024年6月

    出版者・発行元： Springer

    DOI： 10.1007/s11044-024-09995-z 　

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    Multibody dynamics comprises methodologies for the design and analysis of mechanical systems, with Kalman filters being the principal state estimation methods. The Kalman filters are generally formulated for unconstrained systems, the dynamics of which are described by ordinary differential equations in state-space models. However, multibody systems are constrained systems, and the commonly used method to describe their dynamics involves using differential algebraic equations (DAEs) comprising differential and algebraic equations. The differential equations also include the Lagrange multipliers. Hence, incorporating multibody systems, described by DAEs into the scheme of Kalman filters, cannot be achieved straightforwardly, which facilitates different strategies being addressed. This study develops a novel method for converting DAEs into a state-space model. A transition model of the time derivatives of Lagrange multipliers and a Lagrange multiplier constraint vector are devised and used in the state and output equations, respectively. The continuous- and discrete-time extended Kalman filters (CEKF and DEKF) are constructed using the proposed state-space model, and state estimations are simulated on the benchmark planar four- and five-bar linkages. Further, a demonstration of system observability is conducted, and sensitivity to the initial state estimates is studied. These tests demonstrate that the proposed state-space model achieves observable systems and that both the CEKF and DEKF, constructed using the proposed state-space model, can estimate the states with a wide range of initial conditions.

  29. A Novel and Efficient Hamiltonian Dynamic Analysis Approach for Constraint Force Determination in Flexible Multibody Systems 国際誌 査読有り

    Dong, S, Kuzuno, R, Otsuka, K, Makihara, K

    Journal of Sound and Vibration　588　118517　2024年5月

    出版者・発行元： Elsevier

    DOI： 10.1016/j.jsv.2024.118517 　

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    In the dynamic analysis of flexible multibody systems, Hamiltonian formulations offer advantages in numerical stabilization and systematic handling of systems with varying mass. However, current approaches face challenges. Differential algebraic equations (DAEs) can directly express constraint forces but are computationally inefficient, while ordinary differential equations (ODEs) are more computationally efficient but cannot directly represent constraint forces due to the elimination of the Lagrange multiplier. This paper presents an innovative and efficient dynamic analysis approach based on the Hamiltonian formulation, incorporating velocity transformation and open-constraint coordinate methods. Compared to conventional DAE-based Hamiltonian formulations, our approach conducts analysis efficiently using only independent variables. Compared to conventional ODE-based Hamiltonian formulations, our approach effectively expresses constraint forces through Lagrange multiplier reformulation. Furthermore, when compared to the traditional ODE-based Lagrangian formulation, our approach exhibits superior computational efficiency. Numerical simulations assess our proposed formulation, showing agreement with conventional formulations, shorter calculation time, and alignment with analytical results, confirming the accuracy and usefulness of our approach.

  30. Comparison of Magnetostrictive-Actuated Semi-Active Control Methods Based on Synchronized Switching 国際誌 査読有り

    Li, A, Kobayashi, Y, Hara, Y, Otsuka, K, Makihara, K

    Actuators　13　(4)　143-143　2024年4月12日

    出版者・発行元： MDPI

    DOI： 10.3390/act13040143 　

    eISSN：2076-0825

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    Three distinct synchronized switching circuits based on a magnetostrictive actuator are compared in this paper to examine their control mechanisms and circuit characteristics. These circuits include a semi-active shunt circuit, a semi-active current inversion and amplification circuit, and a semi-active automatic current inversion and amplification circuit. Each circuit type employs an additional electronic switch. The synchronized switching method enables the rational control of the circuit current generated by the magnetostrictive actuator to fulfill any desired control strategy. Simulation and experimental results on a 10-bay truss structure reveal that the three circuits can effectively adjust the polarity of the induced current as needed. The three circuits are then compared to thoroughly analyze their unique characteristics and explain their respective advantages and dis-advantages. Using the comparison results, various options available for control circuit design are demonstrated.

  31. Numerical Study Using Nonlinear Finite-Element Methods Based on Green–Lagrange Strain for Dynamics and Statics of Nonequatorial Space Elevator 国際誌 査読有り

    Kuzuno, R, Dong, S, Takahasi, Y, Okada, T, Shizuno, Y, Otsuka, K, Makihara, K

    Journal of Evolving Space Activities　2　197　2024年

    DOI： 10.57350/jesa.197 　

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    A space elevator consists of a climber, counterweight, and primary structure: the tether. Recently, a nonequatorial space elevator has gained attention owing to its ability to extend the construction range and avoid collisions with spacecraft in the geostationary orbit. Previous research on the tether of the nonequatorial space elevator constructed low-fidelity models, such as a rigid body or a spring–mass system, despite the complexity of its dynamics. This study newly introduced a nonequatorial space elevator model using the Green–Lagrange strain in a nodal position finite-element method and flexible multibody dynamics model for a nonequatorial space elevator formulated via the absolute nodal coordinate formulation, which ensures C1 continuity and bending in the element. Based on the constructed models, this study investigated the primary geometrical factors in the analysis of a nonequatorial space elevator. It also examined the static effect of climber position and the dynamics of the climber's descent in a nonequatorial space elevator. The investigation revealed the cause of the higher-order oscillations occurring in the tether of the nonequatorial space elevator, which are absent in the equatorial configuration.

  32. Fractional-Order Modelling and Dynamic Analysis on a Typical Beam Structure with a Semi-active Particle Damping Equipment 国際誌 国際共著 査読有り

    Xue, C, Ye, J, Kuzuno, R, Otsuka, K, Makihara, K, Xia, Z

    Powder Technology　433　119219　2024年1月

    出版者・発行元： Elsevier

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    Semi-active particle damping equipments exhibit considerable adaptability when implemented in flexible structures. However, their dynamic characteristics become complex due to the presence of a substantial quantity of particles within the damping equipment, and the influence of the internal magnetic field necessitates careful consideration. The fractional-order model of this kind of equipment is established, wherein the designed parameters kp and α are respectively associated with the filling ratio and the input current. Depending on the Hertz-Mindlin contact model, the multi-body dynamic issues inner the damping equipment are addressed using the Discrete Element Method, and then the fractional-order parameters kp and α are identified based on the energy distribution observed within a single vibration period. The numerical simulations, conducted using the fractional-order model, show a fundamental consistency with the experimental results. This alignment serves to validate the accuracy and feasibility of the fractional-order model. Finally, the fractional-order model is utilized to investigate the optimized value of the input current and to analyze the motion trajectory of the damping equipment under various scenarios. The results indicate that the optimized input current is approximately 2.5 A; and as the parameter kp and α increase, the motion trajectory of the system will rotate in a counterclockwise direction, accompanied by a gradual outward displacement of the outermost curve relative to the origin position.

  33. Establishment of Iterative Modeling Method for Spherical Tensegrity Structure Using Rotational Symmetry and Regular Polyhedron Configuration 国際誌 査読有り

    Mori, E, Matsumoto, Y, Kawabata, N, Otsuka, K, Makihara, K

    Mechanics Research Communications　135　104217　2024年1月

    出版者・発行元： Elsevier

    DOI： 10.1016/j.mechrescom.2023.104217 　

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    Tensegrity structures are attractive light-weight structures. In particular, spherical tensegrity structures are expected to be applied in various fields. This article proposes a simple method for modeling spherical tensegrities. Firstly, the nodal coordinates of the spherical tensegrity are systematically determined based on rotational symmetry and regular polyhedral configuration. This approach enables the systematic acquisition of the nodal coordinates of spherical tensegrities of all sizes by introducing a three-dimensional rotation matrix and the dihedral angle of the regular polyhedron. Secondly, the prestress ratio is determined iteratively. For the stability analysis of the spherical tensegrity, nonlinear analysis with prestress is required. For the analysis considering the prestress, a tangent stiffness matrix is applied in this study. The simple determination method enables the modeling of spherical tensegrities. The natural frequencies and mode shapes of the spherical tensegrity are identified by frequency analysis. A vibration experiment is conducted as a verification experiment. The natural frequencies from the analysis are compared to the resonance frequencies from the experiment. This comparison confirms the validity of the frequency analysis results, based on the two proposed methods.

  34. Magnetostrictive-Based Induced Current Inversion and Amplification: Semi-Active Vibration Suppression for Multiple-Degree-of-Freedom Flexible Structures with Zero Energy Consumption 国際誌 査読有り

    Li., A, Kobayashi, Y, Hara, Y, Otsuka, K, Makihara, K

    Journal of Sound and Vibration　568　118069　2024年1月

    出版者・発行元： Elsevier

    DOI： 10.1016/j.jsv.2023.118069 　

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    Vibration suppression technology is indispensable in the operation of multiple-degree-of-freedom (MDOF) structures. Properties such as a light weight and reliability are essential for an MDOF structure. However, truss structures tend to be flexible and susceptible to vibration from external influences. Hence, vibration suppression for MDOF flexible structures is necessary. This paper proposes a new semi-active vibration suppression method with a magnetostrictive transducer that can be applied to vibration suppression of an MDOF flexible structure. The proposed method is achieved through an electrical control circuit consisting a magnetostrictive transducer, an inversion capacitor, an electronic switch, and diodes. The control input of the proposed method is considered the induced current. With strategic selection of the circuit statuses, the amplitude of the induced current can be inversed and amplified. Our proposed control strategy is to control the circuit statuses so that the vibration suppression performance can be as effective as possible. The control strategy is determined based on the vibration displacement and velocity of the structure. Numerical simulations were performed to predict the vibration suppression performance. Subsequently, validation experiments were performed using a vibrating cantilevered truss structure, which was considered an MDOF structure composed of many aluminum bar members and iron joints. Under various experimental conditions, the proposed method achieved suppression rates of 12.1–26.7%. The results validated that the proposed method is more effective than a conventional passive method for the vibration suppression of an MDOF flexible structure. The proposed method may aid in ensuring the safe operation of MDOF flexible structures, such as trusses, under extreme conditions.

  35. Multibody Constraints in the Geometrically-Nonlinear Intrinsic Formulation 国際誌 国際共著 査読有り

    Wang, Y, Otsuka, K

    ASME Journal of Computational and Nonlinear Dynamics　18　(12)　121007　2023年12月

    出版者・発行元： ASME

    DOI： 10.1115/1.4063724 　

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    The intrinsic formulation for geometrically-nonlinear beam dynamics provides a compact and versatile description of slender beam-like structures. With nonlinearities limited to second-order couplings in the formulation, it has been an attractive choice in formulating nonlinear reduced-order models for dynamic analysis and control design in aeroelasticity problems involving large displacements and rotations. Owing to its rotation-free formalism, the intrinsic formulation has not been formulated to accommodate multibody constraints, limiting its use against multibody structures with kinematic constraints. This work aims to address such weakness as we present developments in introducing multibody constraints into the full and reduced-order intrinsic equations while still preserving the beneficial traits of the method. We describe the resolution of displacement-level constraints using index-1 approach and adaptation of constraint stabilisation strategies to the intrinsic formulation using state projection. The numerical behaviour of the full- and reduced-order implementations are assessed using test cases with large static and dynamic deformations with time-domain simulations to demonstrate validity of the approach.

  36. Performance of Magnetostrictive Small Wind Turbine using Fe–Co Base Clad Films 国際誌 査読有り

    Ueno, T, Nakaki, T, Mukogawa, T, Dong, S, Kurita, H, Otsuka, K, Makihara, K, Narita, F

    Advanced Engineering Materials　25　(19)　2300185　2023年7月

    出版者・発行元： John Wiley

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    In this study, the Fe–Co alloy was combined with cobalt ferrite (CoFe2O4) and nickel (Ni) to form Fe–Co/CoFe2O4 and Fe–Co/Ni clad sheets and their energy-harvesting performance was evaluated. The Fe–Co/CoFe2O4 clad sheet exhibited an output voltage of 4.229 mV and an output power of 6.89 nW at a wind speed of 10 m/s. The energy-harvesting performance of both these clad sheets could not be quantitatively compared owing to their different thicknesses, which result in varying volume and distance from the neutral plane. Nevertheless, the values of output voltage and power for Fe–Co/CoFe2O4 were higher than those for Fe–Co/Ni (2.107 mV and 0.294 nW).

  37. Energy Harvesting Using Magnetostrictive Transducer Based on Switch Control 国際誌 国際共著 査読有り

    Li, A, Goto, K, Kobayashi, Y, Hara, Y, Jia, Y, Shi, Y, Soutis, C, Kurita, H, Narita, F, Otsuka, K, Makihara, K

    Sensors and Actuators: A. Physical　355　114303　2023年6月

    出版者・発行元： Elsevier

    DOI： 10.1016/j.sna.2023.114303 　

    ISSN：0924-4247

  38. Hamiltonian Formulation with Reduced Variables for Flexible Multibody Systems Under Linear Constraints: Theory and Experiment 国際誌 査読有り

    Dong, S, Otsuka, K, Makihara, K

    Journal of Sound and Vibration　547　117535　2023年3月

    出版者・発行元： Elsevier

    DOI： 10.1016/j.jsv.2022.117535 　

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    Mechanical structures, such as robot arms in space stations and rockets that are used to support futuristic activities and carry loads in modern society, tend to be flexible owing to their reduced weight. Flexible multibody dynamics is an effective method for analyzing the dynamic motion of flexible structures. Although the Hamiltonian formulation based on the canonical theory is commonly used in multibody dynamics, certain drawbacks exist, such as complexity and computational cost. In this study, a novel flexible multibody dynamics formulation based on canonical theory is proposed with reduced variables to improve computational efficiency. This method formulates the equation of motion using only independent generalized coordinates with the assumption of linear constraint equations and the introduction of the first derivative of the constraint condition. The proposed method is combined with absolute nodal coordinate formulation and the motions of flexible structures are simulated to verify its accuracy and effectiveness. In comparison with the conventional methods, the proposed method requires less calculation time while maintaining accuracy. In addition, a wind tunnel experiment was conducted to validate the proposed method. The concurrence between the simulation and experimental results further verifies the accuracy of the proposed method.

  39. Low-Energy-Consumption Structural Identification with Switching Piezoelectric Semi-Active Input 国際誌 査読有り

    Hara, Y, Otsuka, K, Makihara, K

    Mechanical Systems and Signal Processing　187　(109914)　2023年3月

    出版者・発行元： Elsevier

    DOI： 10.1016/j.ymssp.2022.109914 　

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    Herein, we propose a structural system identification method that uses semi-active inputs generated from piezoelectric transducers. Previous onsite structure identification methods consumed significant amounts of energy to generate input signals and thus could not be actively implemented. The proposed method consumes less energy to generate input signals during identification. Two problems limit the use of semi-active inputs for identification purposes: (1) a control strategy to generate semi-active inputs suitable for identification does not exist, and (2) the polarity of the semi-active input cannot be freely controlled. To solve the first issue, we constructed a semi-active input generation strategy that matches the polarities of semi-active inputs with target signals appropriate for identification. To address the second problem, the mechanism by which polarity control is possible and impossible is clarified based on an analytical solution of a semi-active input generation circuit. A data calibration method focusing on sign similarity was proposed to improve the identification accuracy when polarity control cannot be implemented. The proposed semi-active identification method successfully identified the frequency response of a structure using 98% lesser energy than that used by conventional active methods. The proposed method was validated through simulations and experiments. The proposed method achieved accurate identification and can be used for onsite structural health monitoring.

  40. Strategy for Performance Improvement in Piezoelectric Semi-Active Structural System Identification by Excluding Switching Failures using Pseudo-State Feedback 国際誌 査読有り

    Hara, Y, Tang, T, Otsuka, K, Makihara, K

    Mechanical Systems and Signal Processing　187　(109906)　2023年3月

    出版者・発行元： Elsevier

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    System identification in vibrating structures is useful for structural health monitoring. Onsite structural system identification must be achieved with low energy consumption. Accordingly, semi-active inputs should be considered to apply onsite system identification because they can be generated with low energy consumption. However, conventional identifications that use semi-active inputs could not continuously generate inputs suitable for system identification because of switching failure. Switching failure is caused by the mechanism of the semi-active input generation circuit. Due to switching failure, properties of semi-active inputs deviate from the property suitable for identification. Their results deviate from the results obtained using suitable inputs. Moreover, semi-active identification could not be used for structural health monitoring because they cannot determine the cause of significant variations in the identification results (either because of system identification faults from switching failure or because of structural damage). To solve these drawbacks of semi-active identification, we propose a new strategy to generate semi-active inputs that can realize ideal identification. The proposed strategy has two novelties compared to conventional semi-active identification methods: (1) The strategy prevents switching failures and continuously provides semi-active inputs suitable for identification. (2) The strategy is modeled as an optimization problem and provides appropriate circuit control to generate semi-active inputs suitable for identification by solving binary search. Numerical simulations and experiments confirm that the proposed strategy exhibits better identification performance than the conventional strategies. In addition, small variances are observed in the identification results in all time domains. The semi-active inputs generated by the proposed strategy can contribute to precise structural health monitoring using onsite structural identification because it provides accurate identification results with less variation and energy consumption.

  41. Semi-Active Switching Vibration Control with Tree-Based Prediction and Optimization Strategy 国際誌 査読有り

    Abe, M, Hara, Y, Otsuka, K, Makihara, K

    Journal of Intelligent Material Systems and Structures　34　(4)　440-460　2023年3月

  42. Self-Sensing Method for Semi-Active Structural Identification by Removing Piecewise Bias from Piezoelectric Voltage 国際誌 査読有り

    Hara, Y, Tang, T, Otsuka, K, Makihara, K

    Sensors and Actuators A: Physical　347　113907-113907　2022年11月

    出版者・発行元： Elsevier

    DOI： 10.1016/j.sna.2022.113907 　

    ISSN：0924-4247

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    Structural system identification (SSI) that uses many actuators and sensors will be more accessible as a sensing technology if the number of these devices decreases. Recently, a semi-active SSI using a piezoelectric transducer and a unique semi-active input generation circuit was proposed. The semi-active SSI outperforms conventional SSIs with low energy consumption. If the semi-active input and its vibration response are estimated from the voltage generated by a piezoelectric transducer, some sensors will become redundant. Conventional self-sensing methods estimate structural vibrations without using vibration sensors. The semi-active SSI in combination with the self-sensing method will be more accessible than current technologies from the perspectives of a lower energy consumption and fewer number of devices. However, the following two problems exist: (1) A semi-active input generation circuit cannot introduce conventional hardware-based self-sensing methods with additional electric circuits because the electrical components in the additional circuits degrade the performance of the piezoelectric transducer. (2) Software-based self-sensing methods, such as the Kalman filter, cannot be used in system identification scenarios because the electromechanical parameters and models are unknown. To overcome these drawbacks, a novel software-based self-sensing method that does not require electromechanical models is proposed in this paper, and the effectiveness of the proposed method is thoroughly investigated using both simulations and experiments. The identification performance of the proposed method using the estimated input and output is the same as that using directly measured data. The proposed method can especially contribute to the predictive maintenance of structures in isolated environments.

  43. Dynamics and Energy Analysis of Nonequatorial Space Elevator Using Three-Dimensional Nonlinear Finite Element Method Extended to Noninertial Coordinate System 国際誌 査読有り

    Kuzuno, R, Dong, S, Okada, T, Otsuka, K, Makihara, K

    IEEE Access　10　43964-43980　2022年5月

    出版者・発行元： IEEE

    DOI： 10.1109/ACCESS.2022.3168666 　

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    A space elevator is a futuristic space transportation technology that enables low-cost and versatile payload transportation using climbers on a tether deployed from the geostationary orbit (GEO). In particular, a nonequatorial space elevator, which contains an anchor in a region with latitudes on the Earth, has recently attracted attention. It has several advantages, such as extending the construction range and avoiding collisions with spacecraft in the GEO. Prior research has focused on rigid-body or spring-mass models with low fidelity. This paper proposes a modeling method for nonequatorial space elevators using a nodal-position finite element method (NPFEM) extended to a rotational coordinate system. The NPFEM is a three-dimensional finite element method that considers geometric nonlinearity. Conventional NPFEMs have only been formulated using inertial coordinate systems. This paper proposes a method to formulate the NPFEM in a noninertial coordinate system and derive the inertial forces and Jacobian matrices. In addition, a three-dimensional analysis of a nonequatorial space elevator was performed based on the proposed method. After determining the equilibrium position of the NPFEM, the dynamic response of the tether during climber ascent was analyzed. Moreover, parametric studies were conducted by varying several properties of the nonequatorial space elevator. Furthermore, the energy exchange between the components was analyzed to validate the proposed method and to discuss the energy perspective of the space elevator. The results revealed that the proposed nonequatorial space elevator model experienced a more tensioned equilibrium and exhibited a more significant dynamic response than conventional models.

  44. Comprehensive Predictive Control for Vibration Suppression Based on Piecewise Constant Input Formulation 国際誌 査読有り

    Takamoto, I., Abe, M., Hara, Y., Otsuka, K., Makihara, K.

    Journal of Intelligent Material Systems and Structures　33　(7)　901-917　2022年4月

    DOI： 10.1177/1045389X211038703 　

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    We propose a novel semi-active vibration suppression method based on model predictive control (MPC). Semi-active vibration suppression provides excellent damping performance, energy consumption, and stability during control. As the semi-active control input is often discontinuous, it may be difficult to predict. Hence, we combine semi-active vibration suppression and MPC to determine the control input trajectory arbitrarily. The proposed method, called predictive switching based on piecewise constant input (PSPCI), assumes that the piezoelectric charge remains constant when the control circuit is in the open state. Under this assumption, the future system state can be predicted for semi-active vibration suppression while reducing the computational load. The PSPCI method predicts the future work done by the transducer and effectively suppresses vibrations. Its effectiveness and robustness are demonstrated through simulations and experiments. The proposed PSPCI method enables the prediction of the semi-active control input and diversifies the control input determination for effective semi-active vibration suppression.

  45. Adaptive and Robust Operation with Active Fuzzy Harvester under Nonstationary and Random Disturbance Conditions 国際誌 査読有り

    Hara, Y., Otsuka, K., Makihara, K.

    Sensors　21　(11)　3913　2021年6月

    出版者・発行元： MDPI

    DOI： 10.3390/s21113913 　

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    The objective of this paper is to amplify the output voltage magnitude from a piezoelectric vibration energy harvester under nonstationary and broadband vibration conditions. Improving the transferred energy, which is converted from mechanical energy to electrical energy through a piezoelectric transducer, achieved a high output voltage and effective harvesting. A threshold-based switching strategy is used to improve the total transferred energy with consideration of the signs and amplitudes of the electromechanical conditions of the harvester. A time-invariant threshold cannot accomplish effective harvesting under nonstationary vibration conditions because the assessment criterion for desirable control changes in accordance with the disturbance scale. To solve this problem, we developed a switching strategy for the active harvester, namely, adaptive switching considering vibration suppression-threshold strategy. The strategy adopts a tuning algorithm for the time-varying threshold and implements appropriate intermittent switching without pre-tuning by means of the fuzzy control theory. We evaluated the proposed strategy under three realistic vibration conditions: a frequency sweep, a change in the number of dominant frequencies, and wideband frequency vibration. Experimental comparisons were conducted with existing strategies, which consider only the signs of the harvester electromechanical conditions. The results confirm that the presented strategy achieves a greater output voltage than the existing strategies under all nonstationary vibration conditions. The average amplification rate of output voltage for the proposed strategy is 203% compared with the output voltage by noncontrolled harvesting.

  46. Piezoelectric Energy Enhancement Strategy for Active Fuzzy Harvester with Time-Varying and Intermittent Switching 国際誌 査読有り

    Hara, Y., Zhou, M., Li, A., Otsuka, K., Makihara, K.

    Smart Materials and Structures　30　(1)　015038　2021年1月1日

    出版者・発行元：

    DOI： 10.1088/1361-665x/abca08 　

    ISSN：0964-1726

    eISSN：1361-665X

    詳細を見る 詳細を閉じる

    This study aims to increase the amount of electrical energy harvested from a piezoelectric vibration energy harvester under unloaded and high-load resistance conditions. Although increased piezoelectric charge due to the synchronized switch harvesting on inductor (SSHI) strategy damps mechanical vibrations, the mechanical vibration amplitude of a mechanical element in a harvester is assumed to be constant for most discussions regarding the active harvester with SSHI strategy. However, this assumption is not valid under excessive switching actions, in which case the performance of the harvester deteriorates. This problem is known as the vibration suppression effect. To address this problem, in this study, two switching strategies for the charge inversion circuit—namely, switching considering vibration suppression-threshold (SCVS-t) and adaptive SCVS-t (ASCVS-t)—are proposed through intermittent switching actions. During the harvesting process, intermittent switching using these strategies is performed based on the output voltage threshold, thus maintaining high mechanical vibration amplitude and excellent harvesting performance by avoiding excess switching. The ASCVS-t adopts a tuning algorithm for the time-varying threshold and can achieve appropriate intermittent switching and effective harvesting under various vibration conditions without pre-tuning. Experimental comparisons with conventional strategies confirm that the proposed strategies achieve 2.9 times and 2.0 times greater harvested energy storages than a standard harvester and conventional switching strategy, respectively.

  47. Predictive Switching Vibration Control Based on Harmonic Input Formulation 国際誌 査読有り

    Takamoto, I., Abe, M., Hara, Y., Nakahara, T., Otsuka, K., Makihara, K.

    Sensors and Actuators, A: Physical　315　112271　2020年11月1日

    出版者・発行元：

    DOI： 10.1016/j.sna.2020.112271 　

    ISSN：0924-4247

︎全件表示 ︎最初の5件までを表示

書籍等出版物 1

  1. 現象の本質を捉えるための賢い解析モデルの選択 ～フィデリティとは何か？～

    大塚啓介

    日本機械学会　2022年6月

    DOI： 10.1299/jsmemag.125.1243_40 　

講演・口頭発表等 126

  1. Moving Wide Bezier Components with Constrained Ends-Based Evolutionary Topology Optimization for Turbulent Pipe Systems 国際会議

    Kazuya Urata, Kentaro Yaji, Kikuo Fujita, Keisuke Otsuka

    The 16th World Congres of Structural and Multidisciplinary Optimization (WCSMO-16)　2025年5月20日

  2. 機械学習を用いた熱問題の解析

    加藤 諒, 奥山 敦人, 江口 空希, 原 勇心, 大塚 啓介, 槙原 幹十朗

    日本機械学会東北支部 第60期総会・講演会　2025年3月17日

  3. 機械学習を活用したMMCトポロジー最適化

    川合元伸, 董鑠男, 葛野諒, 静野芳崇, 岡田大規, 永井成哉, 川島柊吾, 槙原幹十朗, 大塚啓介

    日本機械学会東北支部 第60期総会・講演会　2025年3月17日

  4. Thermal Load Estimation Using Machine Learning 国際会議

    Atsuto Okuyama, Ryo Kato, Soraki Eguchi, Yushin Hara, Kanjuro Makihara, Keisuke Otsuka

    21st International Conference on Flow Dynamics (ICFD2024)　2024年11月18日

  5. Nonlinear Aeroelastic Simulation Framework with Machine Learning for High Aspect Ratio Wings 国際会議 国際共著

    Kento Shimura, Hao He, Hiroki Yamashita, Hiroyuki Sugiyama, Yoshiaki Abe, Takanori Haga, Keisuke Otsuka

    21st International Conference on Flow Dynamics (ICFD2024)　2024年11月18日

  6. Absolute Nodal Coordinate Formulation for Nonlinear Multibody Modeling of Flared Hinged Wings 国際会議 国際共著

    Keisuke Otsuka, Chi Wing Cheng, Rafael Palacios

    34th Congress of the International Council of the Aeronautical Sciences (ICAS2024)　2024年9月9日

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    The wings of transport jets are becoming high aspect ratio to reduce induced drag. Because of the high aspect ratio configuration with lightweight, the wings may undergo nonlinear large deformations induced by aerodynamic forces. To alleviate excessive large deformation under gust conditions, flared hinged wings have been developed. This study develops a new multibody simulation framework for the flared hinged wings based on absolute nodal coordinate formulation (ANCF). In this framework, the constraint equation to describe the flared hinge joint can be written in a simple linear equation. We show that the simulation results of ANCF simulation framework is in good agreement with those of a second simulation framework, namely SHARPy, based on a conventional geometrically-exact beam formulation (GEBF)

  7. Multibody Analysis Comparison between Strain-Based Beam Formulation and Absolute Nodal Coordinate Formulation 国際会議 国際共著

    Keisuke Otsuka, Hiroyuki Sugiyama

    International Conference on Multibody System Dynamics (IMSD2024)　2024年6月12日

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    he wings of recent regional jet tend to have high aspect ratio to reduce induced drag. Because of the high aspect ratio configuration with lightweight, the wings undergo large deformations induced by aerodynamic forces. In addition, such high aspect ratio wings experience very high wing root bending moment when they encounter gust. To alleviate the gust response, a folding wing concept was proposed. When designing the high aspect ratio wings with the folding wing mechanism, a multibody simulation considering geometric nonlinearity is necessary. Owing to the slenderness of the high aspect ratio wing, geometrically nonlinear beam formulations are suitable for the simulation. In this study, two geometrically nonlinear beam formulations are compared in multibody simulations. One is absolute nodal coordinate formualtion (ANCF) and the other is strain-based beam formulation (SBBF). The major difference of them is that ANCF has a constant mass matrix, while SBBF has a constant stiffness matrix.

  8. Moving Morphable Components based on Strain-Based Beam Formulation for Topology Optimization 国際会議 国際共著

    Keisuke Otsuka, Shuonan Dong, Ryo Kuzuno, Hiroyuki Sugiyama, Kanjuro Makihara

    AIAA SciTech 2024 Forum　2024年1月8日

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    Moving morphable component (MMC) framework is a topology optimization method that can directly impose geometrical constraints by using geometrical parameters as design variables, which can enhance the manufacturability of topologically optimized structures. Curvature is a significant geometrical parameter in designing structures because curved topology tends to have less stress concentration than sharp topology, and it is difficult to manufacture excessively curved topology. Therefore, imposing specific constraints on curvature is important. However, conventional MMCs cannot impose curvature constraints directly because they do not use curvature as a design variable. To address this issue, we propose a curvature-based component that possesses curvature as a design variable. The proposed component leverages the curvilinear geometry representation of the strain-based beam formulation, which was originally developed to analyze large deformation of slender structures. However, the geometry representation produces poor convergence and asymmetric topology even when symmetric boundary and load conditions are considered because the origin of the curvilinear coordinate is placed on a curved geometry asymmetrically. Therefore, we propose a symmetric curvature-based component that considers curvilinear coordinates in the negative and positive directions symmetrically. Further, it is demonstrated that the use of a direction vector is better suited than that of a trigonometric function to define the direction of the curvilinear coordinates. We extend the components to multi-curvature-based components that can express more complicated topology. We demonstrate that the proposed components can easily impose the curvature constraints in a benchmark problem, which could enhance the manufacturability of topologically optimized structures.

  9. Analysis-Oriented Moving Morphable Components for Topology Optimization 国際会議

    Keisuke Otsuka, Shuonan Dong, Ryo Kuzuno, Kanjuro Makihara

    AIAA SciTech 2023　2023年1月25日

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    Topology optimization based on moving morphable components efficiently generates a topology that is expressed by a few geometrical design variables. However, conventional moving morphable components have three problems: lack of C1 continuity between components, difficulty in describing a smooth roll-up shape, and difficulty in generating a rigid joint to an optimized topology. In this study, a novel topology optimization framework was developed by introducing theories devised for multibody analysis. First, an adaptive moving morphable component based on absolute nodal coordinate formulation was proposed. Because both the position and gradient are used as design variables, C1 continuity is ensured. Second, a position and gradient connection algorithm leveraging the linear constraint of the absolute nodal coordinate formulation was proposed to describe the smooth roll-up shape. Third, a rigid joint is generated by introducing the gradient constraint equation in an optimizer. The developed framework exhibited superior convergence compared with the conventional one in the benchmark short beam problem. It successfully generated an optimal topology with the intent of a designer, that is, designer-selected topology continuity and rigid joints, which facilitates the assembly and manufacturing of topologically optimized structural members to construct an entire aerospace structure.

  10. Strain-Based Geometrically Nonlinear Beam Formulation for Multibody Dynamic Analysis 国際会議 国際共著

    Keisuke Otsuka, Yinan Wang, Rafael Palacios, Kanjuro Makihara

    AIAA Scitech 2022 Forum　2022年1月4日

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    The geometrically nonlinear strain-based beam formulation has the potential to analyze flexible multibody systems efficiently due to the minimum number of variables and the constant stiffness matrix. The objective of this paper is to extend the strain-based beam formulation to a generic multibody dynamic analysis. To achieve this objective, we describe the constraint equation by using the vector variables of the absolute nodal coordinate formulation that has a velocity-transformation relationship with the strain-based formulation. Then, we divide the Jacobian of the constraint equation into two terms. One term is equivalent to the velocity transformation matrix that has been implemented in the existing strain-based analysis framework. Therefore, additional programming effort and calculation are not needed. The other term is a simple constant or linear Jacobian defined by the orthonormal vectors of the absolute nodal coordinate formulation. This simple Jacobian description enables not only efficient analysis but also various choice of a time-integration method. We demonstrated that the proposed framework can be used with the explicit Runge-Kutta method and the implicit generalized-α method. The proposed strain-based multibody dynamic analysis method exhibited good agreement with and a better convergence than a conventional flexible multibody dynamic analysis method.

  11. Unsteady Aeroelasticity of Slender Wings with Leading-Edge Separation 国際会議 国際共著

    Yinan Wang, Xiaowei Zhao, Rafael Palacios, Keisuke Otsuka

    AIAA Scitech 2021 Forum　2021年1月

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    We present a medium-fidelity aeroelastic framework for computing intermittently separating 3D flows around slender aero-structures with a significantly reduced computational cost than CFD-based method. In which, we propose a modified 3D vortex panel method with leading-edge separation controlled by the leading-edge suction parameter theory, and demonstrate its incorporation in a coupled aeroelastic solver for the dynamic response of these systems. Numerical verifications and simulations are presented on both attached and separated aeroelastic test cases, demonstrating the capability of the proposed method.

  12. Nonlinear Static and Dynamic Analysis Framework for Very Flexible Multibody Aircraft with Propellers 国際会議 国際共著

    Keisuke Otsuka, Alfonso del Carre, Rafael Palacios

    AIAA Scitech 2021 Forum　2021年1月

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    A nonlinear static and dynamic aeroelastic analysis framework for high aspect ratio wings with propellers is described. The aerodynamic effect of propellers is considered. The high computational cost required for modeling aerodynamic interaction between the wing and propeller wake is reduced by taking advantage of the relatively slow dynamics of the wing. Consequently, the propeller wake is modeled as a straight vortex cylinder that does not require a computationally expensive wake updating process. By leveraging the smallness of the propeller, we propose an averaged vortex cylinder method that calculates the induced velocities of the propeller vortex cylinder efficiently without suffering from a numerical singularity and loss of accuracy. The induced velocities are considered in the wing aerodynamic force calculation using an unsteady vortex lattice method. We also propose an efficient propeller cylinder coordinate generation method modeling the propeller-attached wing by absolute nodal coordinate formulation with a multibody dynamic theory. The developed framework is validated by comparison with other frameworks and formulations. A nonlinear static analysis on a representative high-aspect-ratio wing demonstrates that the propeller-induced axial velocity has a larger effect on the increase in deflection than the tangential velocity. The nonlinear dynamic results show that the propeller may decrease the deflection amplitude.

  13. Deployable Wing Model Using ANCF and UVLM: Multibody Dynamic Simulation and Wind Tunnel Experiment 国際会議 国際共著

    Keisuke Otsuka, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

    AIAA SciTech 2020 Forum　2020年1月9日

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    This paper presents a deployable-wing multifidelity modeling method based on an asymmetrically gradient-deficient absolute nodal coordinate formulation coupled with unsteady vortex lattice method. Slender deployable wings are composed of multiple bodies connected by hinge joints and can be deployed or folded spanwise during flight. Low-fidelity and high-fidelity deployment simulation models are required for the conceptual and actual design phases of the wings, respectively. The presented multifidelity modeling method can be used for computationally efficient low-fidelity rigid multibody simulation and more realistic high-fidelity flexible multibody simulation. These multi-fidelity simulations are accomplished using a consistent modeling process and the same simulation program architecture. In addition, a consistent methodology can be used to couple an aerodynamic model with the low-fidelity and high-fidelity structural models. To demonstrate the effectiveness of the presented method, we newly present simulations using benchmark slender wing parameters in this paper. To validate the proposed modeling method, wing deployment experiments were performed in a wind tunnel at the Institute of Fluid Science, Tohoku University. Good agreement was found between the simulation using the presented method and the wind tunnel experiments, even when the wings experienced large geometrically nonlinear deformations.This paper presents a deployable-wing multifidelity modeling method based on an asymmetrically gradient-deficient absolute nodal coordinate formulation coupled with unsteady vortex lattice method. Slender deployable wings are composed of multiple bodies connected by hinge joints and can be deployed or folded spanwise during flight. Low-fidelity and high-fidelity deployment simulation models are required for the conceptual and actual design phases of the wings, respectively. The presented multifidelity modeling method can be used for computationally efficient low-fidelity rigid multibody simulation and more realistic high-fidelity flexible multibody simulation. These multi-fidelity simulations are accomplished using a consistent modeling process and the same simulation program architecture. In addition, a consistent methodology can be used to couple an aerodynamic model with the low-fidelity and high-fidelity structural models. To demonstrate the effectiveness of the presented method, we newly present simulations using benchmark slender wing parameters in this paper. To validate the proposed modeling method, wing deployment experiments were performed in a wind tunnel at the Institute of Fluid Science, Tohoku University. Good agreement was found between the simulation using the presented method and the wind tunnel experiments, even when the wings experienced large geometrically nonlinear deformations.

  14. ANCF-ICE Beam Element for Modeling Highly Flexible and Deployable Aerospace Structures 国際会議

    Keisuke Otsuka, Kanjuro Makihara

    AIAA SciTech 2019 Forum　2019年1月7日

  15. Deployment Simulation Model Based on ANCF Plate Element for Next-Generation Aerospace Structures 国際会議

    Keisuke Otsuka, Kanjuro Makihara

    AIAA SciTech 2018 Forum　2018年1月

  16. Modal Rotation Methodによる柔軟構造の大変形解析

    永井 成哉, 静野 芳崇, 董 鑠男, 葛野 諒, 岡田 大規, 川合 元伸, 川島 柊吾, 槙原, 幹十朗, 大塚 啓介

    日本機械学会東北支部 第60期総会・講演会　2025年3月17日

  17. Buffeting-Induced Vibration Energy Harvesting using Flexible Plates with Piezoelectric Film 国際会議 国際共著

    Kento Shimura, Mizuki Ishigami, Yu Jia, Yu Shi, Constantinous Soutis, Hiroki Kurita, Fumio Narita, Yushin Hara, Kanjuro Makihara, Keisuke Otsuka

    21st International Conference on Flow Dynamics (ICFD2024)　2024年11月18日

  18. Dynamic Analysis Method for High-Aspect-Ratio Wings Using Curvature Modes 国際会議

    Yoshitaka Shizuno, Shuonan Dong, Ryo Kuzuno, Taiki Okada, Naruya Nagai, Motonobu Kawai, Shugo Kawashima, Kanjuro Makihara, Keisuke Otsuka

    21st International Conference on Flow Dynamics (ICFD2024)　2024年11月18日

  19. Numerical Study on Aerodynamic Interaction Between Propeller Wake and Wing in Low-Reynolds Number Flow 国際会議

    Nana Hasegawa, Masahiro Kanazaki, Keisuke Otsuka, Hiroki Nagai

    Asia-Pasific International Symposium on Aerospace Technology (APISAT2024)　2024年10月29日

  20. Simple Shape Finding for Spherical Tensegrity Based on Rotational Location 国際会議

    Kanjuro Makihara, Yuta Matsumoto, Daiki Suzuki, Keisuke Otsuka

    75th International Astronautical Congress (IAC-2024　2024年10月14日

  21. 球状テンセグリティの形状決定における構造変数 の従属性および初期自己応力導出

    松本 佑太, 鈴木 大貴, 原 勇心, 大塚 啓介, 槙原 幹十朗

    日本機械学会東北支部第60期秋季講演会　2024年9月28日

  22. Torsional Effect of Flexible Tether by Eccentric Climber in Space Elevator Including Nonequatorial Anchor 国際会議

    Ryo Kuzuno, Shuonan Dong, Taiki Okada, Yoshitaka Shizuno, Keisuke Otsuka, Kanjuro Makihara

    The 11th Asian Conference on Multibody Dynamics 2024 (ACMD2024)　2024年8月26日

  23. Constraint Force in Focus: An Efficient Hamiltonian Dynamic Analysis for Flexible Multibody Systems 国際会議

    Shuonan Dong, Ryo Kuzuno, Keisuke Otsuka, Kanjuro Makihara

    The 17th International Conference on Motion and Vibration (MoViC2024)　2024年8月6日

  24. 球対称性と回転操作に基づく球面テンセグリティの形状決定法

    槙原 幹十朗, 松本 佑太, 大塚 啓介

    第66回構造強度に関する講演会　2024年7月31日

  25. 空力弾性現象による振動エネルギハーベスティング

    志村 賢人, 向川 大成, 原 勇心, 大塚 啓介, 槙原 幹十朗

    日本機械学会東北支部 第59期総会・講演会　2024年3月15日

  26. 非赤道上宇宙エレベータの3 次元動解析の高精度化

    葛野 諒, Dong Shuonan, 髙橋 侑也, 岡田 大規, 大塚 啓介, 槙原幹十朗

    日本機械学会第 32 回スペース・エンジニアリング・コンファレンス　2023年11月23日

  27. Simulation Framework for Wake-Induced Aeroelastic Phenomena 国際会議

    Keisuke Otsuka, Yoshiaki Abe, Tomoki Yamazaki, Takanori Haga

    20th International Conference on Flow Dynamics (ICFD2023)　2023年11月7日

  28. Aeroelastic Simulation Framework for Membrane Wings 国際会議

    Keisuke Otsuka, Shuonan Dong, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

    20th International Conference on Flow Dynamics (ICFD2023)　2023年11月8日

  29. Arbitrary Lagrangian-Eulerian Non-liner Finite Element Analysis of Tethered Structure with Large Deformation 国際会議

    Yuya Takahashi, Ryo Kuzuno, Shuonan Dong, Taiki Okada, Yoshitaka Shizuno, Keisuke Otsuka, Kanjuro Makihara

    20th International Conference on Flow Dynamics (ICFD2023)　2023年11月6日

  30. Flutter Harvester Using Flexible Plates with Piezoelectric Film 国際会議 国際共著

    Taisei Mukogawa, Shuonan Dong, Yu Jia, Yu Shi, Constantinous Soutis, Hiroki Kurita, Fumio Narita, Keisuke Otsuka, Kanjuro Makihara

    20th International Conference on Flow Dynamics (ICFD2023)　2023年11月6日

  31. State Estimation of Multibody Model Using State Observer Based on Differential Algebraic Equation 国際会議

    Taiki Okada, Shuonan Dong, Ryo Kuzuno, Yuya Takahashi, Yoshitaka Shizuno, Keisuke Otsuka, Kanjuro Makihara

    20th International Conference on Flow Dynamics (ICFD2023)　2023年11月6日

  32. Effective Semi-Active Energy Harvesting from Structural Vibration Using Magnetostrictive Transducer 国際会議

    Yuusuke Kobayashi, An Li, Keisuke Otsuka, Kanjuro Makihara

    20th International Conference on Flow Dynamics (ICFD2023)　2023年11月6日

  33. Structural Optimization of Flexible Multibody Systems with Deployment Mechanism 国際会議

    Satoshi Watanabe, Shuonan Dong, Keisuke Otsuka, Kanjuro Makihara

    20th International Conference on Flow Dynamics (ICFD2023)　2023年11月6日

  34. High-Precision Multibody Model for Space Elevator Including Torsional Deformation 国際会議

    Ryo Kuzunoa, Shuonan Dong, Yuya Takahashi, Keisuke Otsuka, Kanjuro Makihara

    74th International Astronautical Congress (IAC)　2023年10月3日

  35. 外乱の周期情報を利⽤した⼊⼒定式化に基づくセミアク ティブ予測振動制御

    三島 光翼, 唐 天乙, 周 蒙, 李 星志, 原 勇心, 大塚 啓介, 槙原 幹十朗

    日本機械学会東北支部 第59期秋季講演会　2023年9月30日

  36. 部分熱硬化型インフレータブル構造物のデブリ防護性能評価

    高橋 輝, 森本 大介, 杉山 喜洋, 大塚 啓介, 槙原 幹十朗

    日本機械学会東北支部 第59期秋季講演会　2023年9月30日

  37. Energy Saving Structural Health Monitoring Using Semi-Active Identification 国際会議

    Yushin Hara, Tianyi Tang, Keisuke Otsuka, Kanjuro Makihara

    Asia Pacific Conference of the Prognostics and Health Management Society (PHMAP 2023)　2023年9月12日

  38. 磁歪トランスデューサを用いた大型振動構造物の効率的なエネルギハーベスティングのためのスイッチング制御方法

    李 安, 小林 佑輔, 原 勇心, 大塚 啓介, 槙原 幹十朗

    Dynamics and Design Conference 2023　2023年8月31日

  39. 準受動制御を用いた省エネルギなモードパラメータの同定

    原勇心, 唐 天乙, 大塚 啓介, 槙原 幹十朗

    Dynamics and Design Conference 2023　2023年8月30日

  40. 幾何学的制約を導入可能なMMC法によるトポロジー最適化

    大塚啓介, Dong Shuonan, 槙原幹十朗

    第65回構造強度に関する講演会　2023年8月10日

  41. ハミルトニアン形式の柔軟マルチボディダイナミクスの低次元化モデリング法と実験実証

    Dong Shuonan, 大塚啓介, 槙原幹十朗

    第65回構造強度に関する講演会　2023年8月8日

  42. System Identification of Space Structures Subjected to Unknown Disturbances Using Piezoelectric Device 国際会議

    Tianyi Tang, Yushin Hara, Meng Zhou, Mizuki Abe, Keisuke Otsuka, Kanjuro Makihara

    The 34th International Symposium on Space Technology and Science (ISTS2023)　2023年6月7日

  43. Dominant Geometrical Factor in Non-Equatorial Space Elevator Dynamics 国際会議

    Ryo Kuzuno, Shuonan Dong, Yuya Takahashi, Taiki Okada, Yoshitaka Shizuno, Keisuke Otsuka, Kanjuro Makihara

    The 34th International Symposium on Space Technology and Science (ISTS2023)　2023年6月6日

  44. Piezoelectric Semi-Active Structural Identification Method to Realize Energy-Saving On-Orbit Identification 国際会議

    Yushin Hara, Tianyi Tang, Keisuke Otsuka, Kanjuro Makihara

    The 34th International Symposium on Space Technology and Science (ISTS2023)　2023年6月7日

  45. Phase-Delay Switching Strategy for Piezoelectric Vibration Energy Harvesting 国際会議 国際共著

    Meng Zhou, Yushin Hara, Tianyi Tang, Yu Jia, Yu Shi, Constantinos Soutis, Hiroki Kurita, Fumio Narita, Keisuke Otsuka, Kanjuro Makihara

    The 34th International Symposium on Space Technology and Science (ISTS2023)　2023年6月6日

  46. 非線形有限要素法によるテザー構造物の大変形解析

    髙橋 侑也, 葛野 諒, Dong Shuonan, 岡田 大規, 静野 芳崇, 大塚 啓介, 槙原 幹十朗

    日本機械学会東北支部 第58期総会・講演会　2023年3月17日

  47. 磁歪トランスデューサを用いた実用的なセミアクティブ振動発電手法の研究

    小林 佑輔, 後藤 慧樹, 李 安, 原 勇心, 大塚 啓介, 槙原 幹十朗

    日本機械学会東北支部 第58期総会・講演会　2023年3月17日

  48. 大変形する展開構造物の構造最適化

    渡辺 聡史, Dong Shuonan, 大塚 啓介, 槙原 幹十朗

    日本機械学会東北支部 第58期総会・講演会　2023年3月17日

  49. Structural Modal Parameter Identification Incorporating with Semi-Active Piezoelectric Control 国際会議

    Hara, Y, Asanuma, H, Otsuka, K, Makihara, K

    SPIE Conference, Smart Structures + Nondestructive Evaluation　2023年3月15日

  50. 航空機・車両・鉄道・エレベータに対する統一的な柔軟マルチボディ解析法の構築

    大塚啓介, Dong Shuonan, 葛野諒, 槙原幹十朗

    第31回 交通・物流部門大会（TRANSLOG2022）　2022年12月1日

  51. Unsteady Characteristics of Membrane Wing Applied Dielectric Elastomer Actuator 国際会議

    Tatsuya Kobayashi, Koji Fujita, Keisuke Otsuka, Hiroki Nagai

    19th International Conference on Flow Dynamics (ICFD2022)　2022年11月10日

  52. Structural Parameter Estimation for Health Monitoring and Damage Detection based on Subspace Identification 国際会議

    Tianyi Tang, Mizuki Abe, Meng Zhou, Yushin Hara, Keisuke Otsuka, Kanjuro Makihara

    19th International Conference on Flow Dynamics (ICFD2022)　2022年11月10日

  53. Geometrically Nonlinear Beam Model for Slender Multibody Wings 国際会議 国際共著

    Keisuke Otsuka, Yinan Wang, Kelvin Cheng, Shuonan Dong, Koji Fujita, Rafael Palacios, Hiroki Nagai, Kanjuro Makihara

    19th International Conference on Flow Dynamics (ICFD2022)　2022年11月10日

  54. Damage Evaluation for Hollow Cylindrical Tethers with Cross-Shaped Keepers 国際会議

    Nanami Karasawa, Daisuke Morimoto, Hikaru Takahash, Kiyonobu Ohtani, Kesuke Otsuka, Kanjuro Makihara

    19th International Conference on Flow Dynamics (ICFD2022)　2022年11月10日

  55. Investigation of Flutter Velocity and Power Generation with Piezoelectric Film 国際会議 国際共著

    Shuonan Dong, Taisei Mukogawa, Yushin Hara, Keisuke Otsuka, Boyue Chen, Yu Shi, Yu Jia, Constantinos Soutis, Hiroki Kurita, Fumio Narita, Kanjuro Makihara

    19th International Conference on Flow Dynamics (ICFD2022)　2022年11月10日

  56. Semi-Active Energy Harvesting with Magnetostrictive Transducer from Structural Vibration 国際会議 国際共著

    Keiju Goto, An Li, Yushin Hara, Keisuke Otsuka, Hiroki Kurita, Fumio Narita, Paul Lohmuller, Pascal Laheurte, Kanjuro Makihara

    19th International Conference on Flow Dynamics (ICFD2022)　2022年11月9日

  57. 非慣性座標系へ拡張した非線形有限要素法による非赤道上宇宙エレベータの 3次元動解析

    葛野諒, 董鑠男, 高橋侑也, 岡田大規, 静野芳崇, 大塚啓介, 槙原幹十朗

    第66回宇宙科学技術連合講演会　2022年11月1日

  58. Flexible Rotating Multibody Analysis Using Extended NPFEM for NonEquatorial Space Elevator 国際会議

    Ryo Kuzuno, Shuonan Dong, Yuya Takahashi, Taiki Okada, Yoshitaka Shizuno, Keisuke Otsuka, Kanjuro Makihara

    The 6th International Conference on Multibody System Dynamics (IMSD)　2022年10月17日

  59. Effect of Pre-Strain on Dielectric Elastomer Actuator Wing at Low Reynolds Number 国際会議

    Tatsuya Kobayashi, Koji Fujita, Keisuke Otsuka, Hiroki Nagai

    The 2022 Asia-Pacific International Symposium on Aerospace Technology　2022年10月12日

  60. 特徴点同士の位置関係に着目した機械学習によるデブ リクラウド輪郭検出法

    森本 大介, 柄澤 菜々美, 高橋 輝, 大塚 啓介, 槙原 幹十朗

    日本機械学会東北支部 第58期秋季講演会　2022年10月8日

  61. テンセグリティ構造における力密度の適用及び加振実験による力学特性の解析

    後藤卓馬, 川畑成之, 大塚啓介, 槙原幹十朗

    日本機械学会東北支部 第58期秋季講演会　2022年10月8日

  62. 平板翼のフラッタ解析と圧電素子を用いたフラッタ発電実験

    向川大成, Dong Shuonan, 大塚啓介, 槙原幹十朗

    日本機械学会東北支部 第58期秋季講演会　2022年10月8日

  63. Experimental Investigations: Dynamic Analysis of 150-Member Spherical Tensegrity to Identify its Characteristics for Space Application 国際会議

    Kanjuro Makihara, Takuma Goto, Nariyuki Kawabata, Keisuke Otsuka

    73rd International Aeronautical Congress (IAC2022)　2022年9月18日

  64. インフラ構造物の振動エネルギを用いた磁歪スイッチング制御エネルギハーベスティングの研究

    李安, 後藤慧樹, 原勇心, 大塚啓介, 槙原幹十朗

    日本機械学会2022年度年次大会　2022年9月13日

  65. モデル縮約したハミルトニアン形式の柔軟マルチボディシステム解析

    Dong Shuonan, 葛野 諒, 岡田 大規, 静野 芳崇, 大塚 啓介, 槙原 幹十朗

    日本機械学会2022年度年次大会　2022年9月12日

  66. 予測木に基づくモデル予測・最適化アル ゴリズムによるセミアクティブ振動制御 国際共著

    阿部 瑞樹, Tang Tianyi, Zhou Meng, 原 勇心, 大塚 啓介, 槙原 幹十朗

    Dynamics and Design Conference 2022　2022年9月8日

  67. プロペラと主翼の空力干渉を考慮した高アスペクト比翼の非線形空力弾性解析

    大塚 啓介, Dong Shuonan, 槙原 幹十朗

    第64回構造強度に関する講演会　2022年8月5日

  68. 宇宙構造物のための省エネルギなセミアクティブ構造同定

    原 勇心, 唐 天乙, 周 蒙, 大塚 啓介, 槙原 幹十朗

    第64回構造強度に関する講演会　2022年8月3日

  69. 圧電素子を用いたセミアクティブ手法による構造システム同定

    唐天乙, 周蒙, 原勇心, 大塚啓介, 槙原幹十朗

    日本機械学会東北支部 第57期総会・講演会　2022年3月11日

  70. 柔軟宇宙構造物における磁歪トランスデューサを用いたセミアクティブ振動発電

    後藤慧樹, 李安, 渡辺大志, 原勇心, 槙原幹十朗, 大塚啓介

    日本機械学会東北支部 第57期総会・講演会　2022年3月11日

  71. Energy Harvesting Using Magnetostrictive Material Based on Active Control 国際会議 国際共著

    An Li, Taishi Watanabe, Yushin Hara, Yu Jia, Yu Shi, Constantinos Soutis, Keisuke Otsuka, Kanjuro Makihara

    33rd International Symposium on Space Technology and Science (ISTS2022)　2022年3月3日

  72. Development of Multibody Dynamics Formulation Based on Canonical Theory 国際会議 国際共著

    Shuonan Dong, Keisuke Otsuka, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

    33rd International Symposium on Space Technology and Science (ISTS2022)　2022年3月1日

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    In modern society, the application of space structures, such as rockets and space stations, are becoming increasingly frequent into the exploration of outer space. Multibody dynamics is an effective method to analyze the dynamic motion of the space structures. As the weight reduction is important for space structures, the flexibility needs to be considered. In this paper, we introduce the Lagrangian formulation and Hamiltonian formulation to describe the multibody systems with use of the Lagrange’s undetermined multipliers method. Lagrangian formulation uses the genialized coordinates as the variables to derive the equation of motion. On the other hand, based on the canonical theory, Hamiltonian formulation uses the generalized coordinates and canonical conjugate momentum. Each formulation is combined with Absolute Nodal Coordinate Formulation, one of the nonlinear finite element methods, to describe the elastic deformation. We compare the behavior of Lagrangian formulation and Hamiltonian formulation by performing the numerical simulation. Two methods show good agreement in the simulation results of the generalized coordinates. However, different methods show different results of generalized momentum in the Hamiltonian formulation, which leads to the careful awareness of selecting constraint levels.

  73. Nonlinear Aeroelastic Analysis Coupling Unsteady Vortex Lattice Method and Strain-Based Beam Formulation 国際会議 国際共著

    Keisuke Otsuka, Shuonan Dong, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

    18th International Conference on Flow Dynamics (ICFD2021)　2021年10月29日

  74. Shape Keepers of Hollow Cylindrical Tethers for Space Debris Removal 国際会議

    Mayumi Suzuki, Ryohei Kobayashi, Nanami Karasawa, Daisuke Morimoto, Kiyonobu Ohtani, Keisuke Otsuka, Kanjuro Makihara

    18th International Conference on Flow Dynamics (ICFD2021)　2021年10月29日

  75. Penetration Evaluation of Inflatable Space Structure with Heat Curing at Hypervelocity Impact 国際会議

    Ryohei Kobayashi, Mayumi Suzuki, Nanami Karasawa, Daisuke Morimoto, Keisuke Otsuka, Kanjuro Makihara

    18th International Conference on Flow Dynamics (ICFD2021)　2021年10月28日

  76. Iterative Modeling and Dynamic Analysis of Spherical Tensegrity 国際会議

    Erina Mori, Takuma Goto, Nariyuki Kawabata, Keisuke Otsuka, Kanjuro Makihara

    18th International Conference on Flow Dynamics (ICFD2021)　2021年10月27日

  77. New MMC-Based Topology Optimization Method with Curvilinear Representation 国際会議

    Shunsuke Hirotani, Shuonan Dong, Ryo Kuzuno, Taiki Okada, Keisuke Otsuka, Kanjuro Makihara

    18th International Conference on Flow Dynamics (ICFD2021)　2021年10月27日

  78. Experimental Investigation of Flutter Power Generation with Piezoelectric Film 国際会議 国際共著

    Kei Imagawa, Keisuke Otsuka, Yu Jia, Yu Shi, Constantinos Soutis, Hiroki Kurita, Fumio Narita, Kanjuro Makihara

    18th International Conference on Flow Dynamics (ICFD2021)　2021年10月27日

  79. Enhancing Piezoelectric Harvested Energy of an Advanced Switching Interface by Tunable Switching Intervals 国際会議 国際共著

    Meng Zhou, Yushin Hara, Yu Jia, Yu Shi, Constantinos Soutis, Hiroki Kurita, Fumio Narita, Keisuke Otsuka, Kanjuro Makihara

    18th International Conference on Flow Dynamics (ICFD2021)　2021年10月27日

  80. Optimization of Electromechanical Dynamic Vibration Absorber for Flexible Space Structure 国際会議

    Taishi Watanabe, An Li, Keiju Goto, Yushin Hara, Keisuke Otsuka, Kanjuro Makihara

    18th International Conference on Flow Dynamics (ICFD2021)　2021年10月27日

  81. Battery-Less Soft Sensor of Spacecraft Vibration with Advanced Piezoelectric Energy Harvester

    Yushin Hara, Li An, Meng Zhou, Keisuke Otsuka, Kanjuro Makihara

    72nd International Aeronautical Congress (IAC2021)　2021年10月29日

  82. Model Predictive Control for Switching Vibration Suppression Using Future Trajectory 国際会議

    Kanjuro Makihara, Mizuki Abe, Yushin Hara, Keisuke Otsuka

    72nd International Aeronautical Congress (IAC2021)　2021年10月29日

  83. テザー破断に着目したスペースデブリ衝突のリスク評価

    柄澤菜々美, 小林稜平, 鈴木麻友美, 森本大介, 大塚啓介, 槙原幹十朗

    日本機械学会東北支部 第57期秋季講演会　2021年10月2日

  84. 非赤道上宇宙エレベータにおけるテザーの３次元非線形解析

    葛野諒, 董鑠男, 廣谷俊輔, 大塚啓介, 槙原幹十朗

    日本機械学会東北支部 第57期秋季講演会　2021年10月2日

  85. Absolute Nodal Coordinate Formulations for Aeroelastic Analysis of Next-Generation Aircraft Wings 国際会議 国際共著

    Otsuka, K., Dong, S., Makihara, K.

    17th International Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC)　2021年8月17日

  86. 歪を要素変数とする非線形梁要素の柔軟マルチボディ解析への拡張

    大塚啓介, Dong Shuonan, 槙原幹十朗

    第63回構造強度に関する講演会　2021年8月6日

  87. ファジィ適応制御を用いた間欠スイッチングハーベスタ

    原勇心, 周蒙, 大塚啓介, 槙原幹十朗

    第63回構造強度に関する講演会　2021年8月4日

  88. 熱硬化型居住用インフレータブル構造物の超高速衝突時における損傷評価

    小林稜平, 富﨑帆乃花, 鈴木麻友美, 柄澤菜々美, 大塚啓介, 槙原幹十朗

    日本航空宇宙学会北部支部２０２１年講演会　2021年3月19日

  89. 磁歪素子を用いた動吸振器による柔軟宇宙構造物の振動制御

    渡辺大志, 李安, 原勇心, 大塚啓介, 槙原幹十朗

    日本機械学会東北支部 第56期総会・講演会　2021年3月12日

  90. スペースデブリ除去用中空円筒テザーの形状保持に関する研究

    鈴木麻友美, 富﨑帆乃花, 小林稜平, 柄澤菜々美, 大塚啓介, 槙原幹十朗

    日本機械学会東北支部 第56期総会・講演会　2021年3月12日

  91. Energy Harvesting Based on Synchronous Inversion and Charge Extraction Circuit Considering Vibration Suppression Effect

    Meng Zhou, 原勇心, 髙本育弥, 大塚啓介, 槙原幹十朗

    日本機械学会東北支部 第56期総会・講演会　2021年3月12日

  92. 大変形を伴う板振動に関する研究

    今川慶, 大塚啓介, 槙原幹十朗

    日本機械学会東北支部 第56期総会・講演会　2021年3月12日

  93. Multibody Modeling Using Absolute Nodal Coordinate Plate Element for Deployable Aerospace Structures 国際会議

    Keisuke Otsuka, Shuonan Dong, Shunsuke Hirotani, Ryo Kuzuno, Kanjuro Makihara

    The 15th International Conference on Motion and Vibration Control (MoViC2020)　2020年12月8日

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    Future aerospace structures, such as Mars aircraft and flapping wing aircraft, have deployable/foldable and thin plate-like components connected by hinge joints. A deployment simulation is necessary to design the structures. Multibody dynamics (MBD) to model the joints coupled with a nonlinear finite element method is an effective approach to perform the simulation. In this study, a plate element based on absolute nodal coordinate formulation (ANCF) is coupled with MBD. ANCF plate element can express large rigid body motion and large elastic deformation including wing-chord deformation, and thus it is suitable for modeling low aspect ratio and very thin wings. However, the ANCF plate element has highly nonlinear elastic force leading to computational inefficiency. To overcome this computational inefficiency, we modify the elastic force formulation of the ANCF plate element by taking advantage of the wing characteristic. By using the ANCF plate element with the modified elastic force, we simulate the deployment motion of a multibody system.

  94. Flexible Multibody Dynamics Using Absolute Nodal Coordinate Formulation with Internal Constraint Equation 国際会議

    Keisuke Otsuka, Shuonan Dong, Shunsuke Hirotani, Ryo Kuzuno, Kanjuro Makihara

    The 15th International Conference on Motion and Vibration Control (MoViC2020)　2020年12月8日

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    Next-generation aerospace structures, such as deployable wing aircraft, consist of very flexible bodies connected by joints because they are required to be lightweight. In designing the structures, a deployment simulation considering the high flexibility and joint is necessary. Multibody dynamics with absolute nodal coordinate formulation (ANCF) is effective for the simulation. ANCF is a nonlinear finite element method that can easily describe flexible deformation and constraint joint equations. However, ANCF cannot be easily applied to complicated cross-sectional structures such as a wing. This is because the volume integral necessary for the elastic force derivation is difficult for complicated structural shapes. To solve this problem, we present an ANCF beam element with internal constraint equations (ICE). ICE restricts the non-dominant deformation. Consequently, a line integral can be used instead of the volume integral. We demonstrate that the ANCF-ICE beam element can describe the very flexible deformation of a complicated cross-sectional structure in a flying wing simulation.

  95. Multibody Dynamic Analysis Based on Canonical Theory

    Shuonan Dong, Keisuke Otsuka, Kanjuro Makihara

    17th International Conference on Flow Dynamics (ICFD2020)　2020年10月29日

  96. Flexible Wing Fluid-Structure Interaction Model Coupling Unsteady Vortex Lattice Method and Absolute Nodal Coordinate Formulation 国際会議 国際共著

    Keisuke Otsuka, Shuonan Dong, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

    17th International Conference on Flow Dynamics (ICFD2020)　2020年10月29日

  97. 弾性力を簡易化したANCF/CRBF梁モデルの運動解析

    廣谷俊輔, Dong Shuonan, 大塚啓介, 槙原幹十朗

    日本機械学会東北支部第56期秋季講演会　2020年9月26日

  98. 回転対称性を利用した球状テンセグリティのモデリング手法の確立

    森瑛梨奈, 原勇心, 大塚啓介, 槙原幹十朗

    日本機械学会東北支部第56期秋季講演会　2020年9月26日

  99. 展開型モーフィング翼のマルチフィデリティ構造空力連成解析 招待有り

    大塚啓介

    日本機械学会2020年度年次大会「先端技術フォーラム」　2020年9月15日

  100. 絶対節点座標法を用いた柔軟翼の非線形構造解析

    大塚啓介, Dong Shuonan, 槙原幹十朗

    第62回構造強度に関する講演会　2020年8月5日

  101. 正準理論に基づく柔軟マルチボディシス テムについての研究

    Dong Shuonan, 大塚啓介, 廣谷俊輔, 須崎貴大, 槙原幹十朗

    日本機械学会東北支部第 55 期総会・講演会　2020年3月13日

  102. New Framework of Strain Based Beam Formulation for Rigid Body Motion 国際会議

    Takahiro Suzaki, Keisuke Otsuka, Shunsuke Hirotani, Shuonan Dong, Kanjuro Makihara

    16th International Conference on Flow Dynamics (ICFD2019)　2019年11月8日

  103. Comparison of 2D and 3D Simulation Models for Deployable Wing 国際会議 国際共著

    Keisuke Otsuka, Takahiro Suzaki, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

    16th International Conference on Flow Dynamics (ICFD2019)　2019年11月8日

  104. 鳥の羽を模した折り畳み機構を有する翼のマルチボディ解析

    大塚啓介, 須崎貴大, 藤田昂志, 永井大樹, 槙原幹十朗

    第57回飛行機シンポジウム　2019年10月16日

  105. Strain Based Beam Formulation の発展手法に関する研究

    須崎 貴大, 大塚 啓介, 小貫 慧, 槙原 幹十朗

    日本機械学会東北支部総会・講演会　2019年3月12日

  106. Simulation and Control of Flexible Aero-Structures using Nonlinear Reduced-Order Models 国際会議 国際共著

    Yinan Wang, Keisuke Otsuka, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

    15th International Conference on Flow Dynamics (ICFD2018)　2018年11月9日

  107. Semi-Active Vibration Suppression Using Predictive Theory 国際会議

    Masumi Ueno, Ikuya Takemoto, Keisuke Otsuka, Kanjuro Makihara

    15th International Conference on Flow Dynamics (ICFD2018)　2018年11月8日

  108. Motion Analysis of Flexible Folding Wing with a Hinge Joint Loaded by Gust 国際会議

    Satoru Onuki, Keisuke Otsuka, Takahiro Suzaki, Hiroki Nagai, Koji Fujita, Kanjuro Makihara

    15th International Conference on Flow Dynamics (ICFD2018)　2018年11月8日

  109. Dynamic Simulation of Deployable Wing Mars Airplane 国際会議 国際共著

    Keisuke Otsuka, Yinan Wang, Koji Fujita, Kanjuro Makihara, Hiroki Nagai

    15th International Conference on Flow Dynamics (ICFD2018)　2018年11月7日

  110. 歪量を要素変数とする 3 次元柔軟梁要素の研究

    須崎 貴大, 大塚 啓介, 小貫 慧, 槙原 幹十朗

    日本機械学会東北支部秋季講演会講演論文集　2018年9月7日

  111. 展開型モーフィング翼の柔軟マルチボディシミュレーション

    大塚 啓介, 槙原 幹十朗

    Dynamics & Design Conference　2018年8月

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    <p>Morphing wing technology is to change the wing shape during flight. The technology has a potential to improve aircraft performance dramatically. One of the attractive morphing wings is the wing that can deploy or fold in the wing span direction. Such a morphing wing is called a deployable wing. The wing consists of several wing bodies jointed by hinges. A deployment actuator and a latching system are attached to the hinge. To obtain the good design of the deployable wing, the deployment simulation using a numerical model is necessary. We have proposed the numerical model comprising flexible multibody dynamics using absolute nodal coordinate formulation (ANCF) and unsteady aerodynamics. The model expresses the coupled motion of large aeroelastic deformation and large rigid body rotation. The model has a constant mass matrix, which means that there is no need to consider imaginary forces. However, it is difficult to model the deployment torque considering relative rotation angle between bodies because ANCF uses vectors expressed in a global coordinate system as nodal variables instead of rotation angles. This paper presents a modeling method to overcome this difficulty. Additionally, we model a lathing mechanism that is necessary for the deployment simulation. Finally, parametric deployment wing simulations are conducted to show the applicability of the model.</p>

  112. 全体座標表現に基づく柔軟展開翼の３次元マルチボディ解析法の開発

    大塚啓介, 槙原幹十朗

    第60回構造強度に関する講演会　2018年8月1日

  113. 多自由度宇宙構造物の予測セミアクティブ制振

    上野真澄, 朝比奈慧, 大塚啓介, 槙原幹十朗

    日本航空宇宙学会北部2018年講演会　2018年3月6日

  114. 翼端にヒンジジョイントを有する柔軟折りたたみ翼の突風作用時における運動解析

    小貫慧, 大塚啓介, 須崎貴大, 槙原幹十朗

    日本航空宇宙学会北部2018年講演会　2018年3月6日

  115. 空力弾性変形を考慮したモーフィング翼のマルチボディ解析

    大塚啓介, 槙原幹十朗

    日本航空宇宙学会北部2018年講演会　2018年3月6日

  116. 予測制御に基づく多自由度振動系のセミアクティブ制御

    上野 真澄, 朝比奈 慧, 大塚 啓介, 槙原 幹十朗

    自動制御連合講演会　2017年11月10日

  117. Deployable Wing Simulation Using Flexible Multibody Dynamics 国際会議

    Keisuke Otsuka, Kanjuro Makihara, Hiroki Nagai

    14th International Conference on Flow Dynamics (ICFD2017)　2017年11月2日

  118. 低次元化マルチボディ構造モデルを用いた展開翼の空力弾性解析

    大塚 啓介, 槙原 幹十朗

    Dynamics & Design Conference　2017年8月31日

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    Aviation organizations around the world are developing deployable wings. The wing is composed of some bodies connected by hinge joints with actuators, and thus it can be transformed in the span direction during the flight. Aeroelastic analysis using structural and aerodynamic models is important for the design of the deployable wing. The aeroelastic analysis takes a long calculation time because the structural deformation and unsteady aerodynamic force must be calculated at the same time. This study presents a deployable wing structural model based on multibody dynamics and absolute nodal coordinate formulation for the aeroelastic analysis. To reduce the calculation time, we propose a reduced order structural model of the deployable wing. The reduced order model provides the 18% reduction of the calculation time compared to the full model within 1% error. Additionally, we propose the method of the flutter speed determination in the time-domain using the reduced order structural model. The method can reflect the nonlinearity caused by the mixed motion between the elastic deformation and the rigid body rotation around the hinge joint in the flutter speed determination. In the method, the total energy of the wing is utilized as an index to determine the flutter speed. As a result, we can evaluate all deformations related to the flutter by using one scalar.

  119. 展開挙動シミュレーションと空力弾性解析のための展開翼モデル

    大塚啓介, 槙原幹十朗

    第59回構造強度に関する講演会　2017年8月4日

  120. 予測制御理論を用いたセミアクティブ振動制御

    上野 真澄, 朝比奈 慧, 大塚 啓介, 槙原 幹十朗

    日本機械学会東北支部秋季講演会　2017年

  121. Frequency-Domain Flutter Analysis of Folding Wing based on Flexible Multibody Dynamics 国際会議

    Keisuke Otsuka, Kanjuro Makihara

    The 2016 Asia-Pacific International Symposium on Aerospace Technology (APISAT2016)　2016年10月26日

  122. Deployment Simulation of Morphing Wing 国際会議

    Keisuke Otsuka, Hiroaki Miyazawa, Kanjuro Makihara

    13th International Conference on Flow Dynamics (ICFD2016)　2016年10月11日

  123. Flutter Analysis of Deployable Wing Using Flexible Multibody Dynamics 国際会議

    Keisuke Otsuka, Kanjuro Makihara

    The first International Symposium on Flutter and its Application (ISFA2016)　2016年5月17日

  124. 非定常空気力を受けるモーフィング翼のMBDシミュレーション

    大塚 啓介, 槙原 幹十朗

    日本機械学会東北支部 第51期総会講演会　2016年3月11日

  125. Aeroelastic Simulation Using Absolute Nodal Coordinate Formulation 国際会議

    Keisuke Otsuka, Kanjuro Makihara

    12th International Conference on Flow Dynamics (ICFD2015)　2015年10月28日

  126. Aeroelastic Simulation for Deployable Wing using Flexible Multibody Dynamics 国際会議

    Keisuke Otsuka, Kanjuro Makihara

    30th International Symposium on Space Technology and Science (ISTS2015)　2015年7月9日

︎全件表示 ︎最初の5件までを表示

共同研究・競争的資金等の研究課題 27

  1. 次世代航空機の設計開発に向けたデータ駆動型の高忠実空力構造連成解析手法の確立 競争的資金

    阿部 圭晃, 大塚 啓介, 芳賀 臣紀, 河野 佑

    提供機関：Japan Society for the Promotion of Science

    制度名：KAKENHI

    研究種目：Grant-in-Aid for Scientific Research (B)

    研究機関：Tohoku University

    2024年4月 ～ 2029年3月

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    水素燃料機・電動機に代表される次世代航空機では，従来機の延長線上に無い設計が要求され，空気力・構造・設計を同時に考慮する数値シミュレーション技術が極めて重要となる．本研究では，既存のモデル駆動型高忠実解析（=方程式を基にした高精度な数値解析）だけでなく，機械学習などに代表されるデータ駆動型のアプローチを導入し，航空工学における空力構造連成解析の新しい方向性を提案・検証することを目的とする．本目的を実現するため，特に離着陸高迎角時の低速バフェット現象（流れの剥離に伴う翼の振動現象）を具体的な問題とし，近年進展著しい炭素繊維複合材料を活用した機体を研究対象とする．

  2. 次世代航空機を実現する３次元静解析と１次元動解析の接続～風洞実証から飛行実証まで 競争的資金

    大塚 啓介, 森田 直人, 志村 賢人

    提供機関：Sumitomo Foundation

    制度名：Research Grant

    研究機関：Tohoku University

    2024年11月 ～ 2026年10月

  3. 次世代ロボット実現に向けた数式変換を代替する AI の構築 競争的資金

    大塚 啓介, 志村 賢人, 平尾 春太

    提供機関：Toyota Physical and Chemical Research Institute

    制度名：Toyota Physical and Chemical Research Scholar

    研究機関：Tohoku University

    2025年4月 ～ 2026年3月

  4. 現実と仮想を融合するAI～浮体式洋上風車のリアルタイム空力弾性解析の実現～ 競争的資金

    大塚 啓介

    提供機関：ENEOS

    制度名：Research Grant

    研究機関：Tohoku University

    2025年4月 ～ 2026年3月

  5. AIが繋ぐロボット工学とマルチボディダイナミクス その他

    大塚 啓介, 槙原 幹十朗, 原 勇心

    提供機関：Hagiwarra Foundation

    制度名：Research Grant

    研究機関：Tohoku University

    2025年4月 ～ 2026年3月

  6. 図面の作成時間をゼロにする図面変数トポロジー最適化 競争的資金

    大塚 啓介

    提供機関：Suzuki Foundation

    制度名：Research Grant

    研究機関：Tohoku University

    2025年4月 ～ 2026年3月

  7. 曲線モードで実現する線形理論に基づく非線形構造解析 競争的資金

    大塚 啓介

    提供機関：Japan Society for the Promotion of Science

    制度名：KAKENHI

    研究種目：Young Researcher

    研究機関：Tohoku University

    2024年4月 ～ 2026年3月

  8. 熱電変換素子を活用したワイヤレスセンサネットワークに基づく宇宙機の温度場モニタリング 競争的資金

    大塚 啓介

    提供機関：The Thermal and Electric Technology Foundation

    制度名：Research Grant

    研究機関：Tohoku University

    2024年12月 ～ 2025年12月

  9. 流体と構造の非線形連成現象を活用した振動発電 競争的資金

    大塚 啓介

    提供機関：Kurita Water and Environment Foundation

    制度名：Research Grant

    研究機関：Tohoku University

    2024年10月 ～ 2025年9月

  10. 低速尾翼バフェットの理論・解析モデルの構築 競争的資金

    大塚 啓介, 阿部 圭晃, 芳賀 臣紀, 志村 賢人

    提供機関：Institute of Fluid Science, Tohoku University

    制度名：General Collaborative Resarch Project

    研究機関：Tohoku University

    2023年4月 ～ 2025年3月

  11. 統一的ベクトル定式化法で実現する膜と骨からなる革新航空機構造の空力弾性解析 競争的資金

    大塚 啓介

    提供機関：Nohmura Foundation for Membrane Structure’s Technology

    制度名：Research Grant 2022

    2023年4月 ～ 2025年3月

  12. 伸展トラス構造観測衛星の低エネルギ消費振動制御を実現する確率的予測制振理論の構築

    槙原 幹十朗, 浅沼 春彦, 大塚 啓介

    提供機関：Japan Society for the Promotion of Science

    制度名：Grants-in-Aid for Scientific Research

    研究種目：Grant-in-Aid for Scientific Research (B)

    研究機関：Tohoku University

    2022年4月 ～ 2025年3月

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    精密観測機器を衛星本体から伸展トラス構造を用いて分離する構造開発では大きな曲げ・ねじり振動が発生するため精密制振が必須課題である．能動制振に要するエネルギは膨大になるので能動制振の実装は困難である．そこで申請者は「圧電電荷を不変量」とする新たな状態モデルを構築し，振動状態の将来予測を初めて可能にした．一方，予測値には確率的な不確定性が含まれ，消費エネルギと制振性能に深刻な悪影響を与えることも明らかになった．そこで本研究では，申請者が独自に提唱し開発を進めている低エネルギ消費の準能動制振の制振性能を飛躍的に向上させる「振動予測技術」を確立する．特に「圧電不変量の確率的不確定性を考慮した外乱予測技術」を導入し，低エネルギ消費と高制振性能を両立する「次世代観測衛星のための確率的予測制振技術」を実現する． 低エネルギ消費と高制振性能を両立する「確率的予測制振」を実現するための確率的予測制振理論の学術的研究及び実証が研究の大目的である．本研究では以下を明らかにした． 【確率的不変量の特性（不変量の確定精度・変動幅）の解明】理論を通して，確率的不変量の確定精度を明らかにした．確率行列理論を用いて確率的不変量の変動幅を理論的に明らかにした．開発している周波数仮定に基づく外乱予測技術を用いて調和振動外乱を精密に予測するとともに振動予測の不確定性を減らした． 10ベイトラス構造を用い，曲げ・捩じり・局所振動を含む複雑振動を生じるようにトラス構造を拡張した．実験と数値計算により，確率的不変量の予測原理に与える影響としてエネルギ消費量と予測性能を定量的に明らかにした．実績値に基づいた数値目標を達成できるかを明らかにした．(1)準能動制振に実行に必要なエネルギ消費量を3.0mW以下に抑えた．

  13. Absolute Nodal Coordinate Formulation for Nonlinear Multibody Modeling of Flared Hinged Wings 競争的資金

    大塚 啓介

    提供機関：Suzuki Foundation

    制度名：Research Grant for International Research Activity

    研究機関：Tohoku University

    2024年9月 ～ 2024年9月

  14. 非線形移動型モデリングによるソフトロボットの構造最適化 競争的資金

    大塚 啓介

    提供機関：Mazak Foundation

    制度名：Research Grant 2022

    研究機関：Tohoku University

    2023年5月 ～ 2024年3月

  15. モード曲線理論が繋ぐ大変形航空機の３次元静解析と１次元動解析 競争的資金

    大塚 啓介

    提供機関：Suzuki Foundation

    制度名：Research Grant 2022

    2023年4月 ～ 2024年3月

  16. 新規理論【ベクトル・回転正準変換】で打破する構造解析と機構解析を分かつ壁 競争的資金

    槙原 幹十朗, 大塚 啓介, 永井 大樹

    提供機関：Japan Society for the Promotion of Science

    制度名：Grants-in-Aid for Scientific Research

    研究種目：Grant-in-Aid for Challenging Research (Exploratory)

    研究機関：Tohoku University

    2022年6月 ～ 2024年3月

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    ＜研究実施の概要＞新規理論【ベクトル・回転正準変換】によって，衛星航空機・浮体式洋上風車などの大変形構造物の構造解析と機構解析を統合する挑戦的研究である．現状は「部材レベルの構造解析に回転角を変数とするモデル」，「システムレベルの機構解析にベクトルを変数とするモデル」が別々に使用されている．回転角モデルはジョイント表現が困難，ベクトルモデルは大変形を正確に表現できないからである．この結果，部材レベルからシステムレベルでの設計に移行する際にモデルを作り直すという致命的な問題が生じる．【異分野を分かつ変数の相違】が構造・機構の両解析分野を分断している障壁である．本研究では部材レベルからベクトルモデリングを行った上で，新規理論【ベクトル・回転正準変換】を導入し，この障壁の打破に挑む．これは変換前のベクトルでジョイント表現，変換後の回転角で高精度解析を実現する新規アイデアである．提案する統合モデリング手法は部材レベルからベクトルモデリングを行うので，【異分野を分かつ変数の相違】が解決され，これまで隔てられていた構造と機構の両解析をシームレスに繋ぐことができる． ＜数値解析と風洞試験＞ ラグランジュ方程式ではなく，正準方程式上で変数変換を行うことでベクトルモデルの長所を一切損なうことなく回転角モデルへの変換を可能となった． ＜実験内容＞ 提案手法の実証のため，東北大学・流体科学研究所の永井教授との共同研究の下，同施設の風洞装置で実験を行った．翼模型を用いて部材レベルでの解析精度実証が可能となった．

  17. 超柔軟膜翼の構造空力連成モデリング理論の構築と実験実証 競争的資金

    大塚 啓介, 永井 大樹, 藤田 昂志, 槙原 幹十朗, Rafael Palacios, Yinan Wang

    提供機関：Institute of Fluid Science, Tohoku University

    制度名：General Collaborative Resarch Project

    研究機関：Tohoku University

    2021年4月 ～ 2024年3月

  18. 非線形移動型モデリング法の構築による大変形構造物の高効率な一連解析 競争的資金

    大塚 啓介

    提供機関：Japan Society for the Promotion of Science

    制度名：Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists

    研究機関：Tohoku University

    2021年4月 ～ 2024年3月

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    災害・コロナ禍の影響を受け，通信需要はますます増加しており，低高度を数年継続飛行することで空の基地局となる衛星航空機の実用化が期待されている．極軽量柔軟な衛星航空機は従来航空機にはありえない大変形が生じるので従来の線形解析法が通用しない．本研究ではこの大変形に伴う非線形性を数式上の任意の位置に移動できる【非線形移動型モデリング法】を構築し，衛星航空機の高効率な解析を可能とする．提案手法による解析性能を東北大学・流体科学研究所の大型風洞装置を用いた実験で実証する．

  19. 歪モデリングと歪センシングを活用した浮体式洋上風車の空力弾性制御 競争的資金

    大塚 啓介

    提供機関：The Ebara Hatakeyama Memorial Foundation

    制度名：Research Grant 2022

    研究機関：Tohoku University

    2022年6月 ～ 2023年3月

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    日本の風車産業において，ブレードは穏やかな風で使用されることが前提の海外輸入品に強く依存してきたが，風向風速が安定しない日本で高出力な浮体式洋上風車を実現するには高い回転効率，首振制御性能を有する革新的な超軽量ブレードが必要となる．軽量化に伴って発生する大きな空力弾性変形（流体と構造の連成）に対して，数学モデルを用いた効率的な制御が求められる．本研究は浮体式洋上風車の大変形ブレードに発生する空力弾性制御モデリングの構築を目的とする．

  20. 超柔軟浮体式洋上風車の実現に向けた空力弾性理論の確立と風洞実験 競争的資金

    大塚 啓介

    提供機関：TEPCO Memorial Foundation

    制度名：Research Grant (General Research)

    研究機関：Tohoku University

    2022年4月 ～ 2023年3月

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    浮体式洋上風車の実現に向けた空力弾性解析理論を構築する研究である．風向風速の安定しない日本で高出力な浮体式洋上風車を実現するには高い回転効率，首振制御性能を有する革新的な超軽量ブレードが必要となる．しかし，軽量化は従来風車には無い大きな空力弾性変形（流体と構造の連成）を引き起こす．本研究では，航空宇宙分野の先進空力弾性解析理論を風車工学に拡張する新規アイデア【ジョイントパラメータ】を提案する．これは回転ジョイント部を含めて浮体式洋上風車の一端から他端までの大変形と剛体運動を高速に漸化計算する独自アイデアである．提案する解析理論を大型風洞実験によって実証する．

  21. 超軽量ブレードを有する浮体式洋上風車の非線形空力弾性解析法の構築 競争的資金

    大塚 啓介

    提供機関：The Iwatani Naoji Foundation

    制度名：The 48th (2021) Iwatani Science Technology Funding

    研究機関：Tohoku University

    2022年4月 ～ 2023年3月

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    「浮体式洋上風車の非線形空力弾性・揺動連成解析理論の構築」が目的である．風向風速が安定しない日本で高出力な浮体式洋上風車を実現するには，高い回転効率と首振制御性能を有する革新的な超軽量ブレードが必要となる（右図）．その結果，日本の浮体式洋上風車は超軽量ブレードの非線形空力弾性変形（流体構造連成で生じる大変形）と波による揺動（風車全体の剛体運動）が連成した複雑挙動が避けられない．浮体式洋上風車の揺動解析理論自体が未成熟であることに加えて，従来の風車工学で想定されていなかった非線形空力弾性変形まで考慮しなければいけない．この新規学術領域に対して，申請者がこれまでの研究で構築した航空機の空力弾性解析法に独自アイデア「ジョイントパラメータ」を導入することで浮体式洋上風車の空力弾性解析基盤を築く．その解析精度を風洞実験で実証する．

  22. 次世代航空機翼の大変形解析と大変形制御を一貫するベクトル歪変換モデリング理論の構築 競争的資金

    大塚 啓介, 槙原 幹十朗

    提供機関：Mazda Foundation

    制度名：The 36th Mazda Research Funding

    研究機関：Tohoku University

    2020年11月 ～ 2022年3月

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    次世代航空機翼の大変形解析と大変形制御を一貫して可能とする数学的モデリング理論の構築が目的である．細長大変形翼を有する次世代航空機の実現には，設計段階での大変形解析だけでなく，リアルタイム計測値と数学モデルを用いた大変形制御が必要となる．しかし，変形解析のみを目的とする従来モデルはリアルタイム計測できないベクトルを変数としていた．本研究では細長形状と幾何学曲線理論の類似性を活用し，ベクトルをリアルタイム計測できる歪に変換する【ベクトル・歪モデリング理論】を提案する．

  23. ベクトル・歪変換式で実現する次世代展開構造物の大変形制御と解析・実験的検証 競争的資金

    大塚 啓介

    提供機関：Japan Society for the Promotion of Science

    制度名：Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity Start-up

    研究種目：Grant-in-Aid for Research Activity Start-up

    研究機関：Tohoku University

    2020年9月 ～ 2022年3月

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    通信・エネルギ・防災の需要増加に伴い，展開翼を有する衛星航空機や高出力大型風車，宇宙・炉心探査用ロボットアームの実用化が期待されている．全長数10mから数100 mに及ぶ細長形状であり，大変形が避けられないこれら次世代構造物を展開するには，実運用中でも計測可能な変形量と数値モデルを用いて，変形を許容内に収める制御が必要である．本研究では実運用中かつ大変形時でも計測が容易な歪を変数とする革新的モデリング法を構築する．構築したモデルによる制御性能を並列計算による高効率解析と東北大学・流体科学研究所における大型風洞実験を通して実証する．

  24. リアルタイム計測歪モデリングで実現する衛星航空機の大変形制御 競争的資金

    大塚 啓介

    提供機関：CASIO Science Promotion Foundation

    制度名：The 38th Research Funding

    研究機関：Tohoku University

    2020年12月 ～ 2021年11月

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    研究代表者が開発中の歪モデリング法で，近年実用化が期待されている衛星航空機の大変形制御系を設計し，その制御性能を風洞実験で実証することが目的である．本研究では無線・光ファイバ歪センサの発達によって，大変形時も計測が容易になってきている歪情報を活用し，スマートアクチュエータによる大変形制御実験を実施する．

  25. 柔軟可変翼機の３次元変形・飛行制御系設計を実現する異分野融合モデリング法の創成

    大塚 啓介, Rafael Palacios

    提供機関：Japan Society for the Promotion of Science

    制度名：Overseas Challenge Program for Young Researchers

    研究機関：Imperial College London

    2019年6月 ～ 2019年9月

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    「多数プロペラを有する衛星航空機の構造空力制御連成解析モデルの開発と実装」に従事した．高精度通信の為，長大な柔軟翼を有することで，高高度を長時間飛行する衛星航空機の実用化が期待されている．衛星航空機の設計開発においては，構造・空力・制御を統合した解析手法および解析ツールが必要となる．派遣先はこれまで SHARPy と名付けられた構造空力連成解析・制御系設計ツールを開発してきた．この SHARPy を基に，本派遣研究では以下の２項目を実施した． ①報告者が先行研究で開発した解析手法 ANCF-ICE と SHARPy の比較による妥当性実証 構造独立解析，空力独立解析，構造空力連成解析を行った．いずれの解析においても，ANCFICE と SHARPy は良好な一致を示し，両者の妥当性を実証することができた．さらに，解析時間や可変機構解析への適用性など両者の長所・短所を見つけだし，今後の両者の発展に繋げることができた． ②プロペラを考慮した構造空力連成解析法の開発と ANCF-ICE および SHARPy への実装 衛星航空機は多数のプロペラを有している．プロペラ後流は構造空力連成挙動に影響を与えるが，プロペラを考慮した効率的な解析手法は確立されていない．本研究では，「衛星航空機の挙動は比較的遅く，航空機近傍ではプロペラ後流が筒状と見なせることに着目」し，効率的な解析手法を提案した．この提案手法を ANCF-ICE と SHARPy の両者に実装し，プロペラが構造空力連成挙動に及ぼす影響を多角的に検証した．

  26. 流体・構造・制御の異分野融合による可変翼モデリング法の確立 （2017-2018年度） 競争的資金

    大塚 啓介

    提供機関：Japan Society for the Promotion of Science

    制度名：Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows (DC2)

    研究種目：Grant-in-Aid for JSPS Fellows

    研究機関：Tohoku University

    2017年4月 ～ 2019年3月

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    次世代航空機は飛行中に折り畳み展開する可変翼の搭載が期待されている．この可変翼の設計開発に必須となる「構造空力連成モデリング法の確立」に向け，以下の３項目に取り組んだ． （１）構造モデルの三次元化・高効率化：絶対節点座標法（ANCF）に基づいた新たな３次元梁要素を開発し，従来困難であった可変挙動・柔軟変形する翼の三次元構造モデリング・シミュレーションを可能とした．ANCFは全体座標で表現されたベクトルのみを変数とし，大変形・大移動する構造物をモデリングできる手法である．しかし，大半の構造物で非支配的となる梁断面の伸縮やせん断を強制的に考慮してしまうため，計算が発散しやすい上に，航空機翼のような複雑断面構造物には適用できないという問題があった．本研究では，ジョイント拘束を取り扱うマルチボディダイナミクス理論を導入し，これら非支配的な断面変形を拘束することで，３次元ANCF梁要素を航空機翼に適用できるように拡張した． （２）空力モデルの高精度化：昨年度までは，初期検討として流体の三次元効果を無視する二次元空力モデルを使用していた．しかし，折り畳み展開する可変翼はスパンが大きく変化するので，流れの三次元効果は無視できなくなることが昨年度の風洞実験で判明した．今回，流れの三次元効果を考慮した三次元空力モデルを提案する構造モデルと連成させることに成功し，シミュレーションと実験はより良好な一致を示した． （３）風洞内変形実験の高精度測定：構築したモデルの精度を実証するために，東北大学・流体科学研究所で可変翼の展開実験を行った．可変翼実験装置の展開機構を電動化することで，よりバラツキの小さい実験データの取得に成功した．さらに，近距離高精度レーザー変位計を導入し，昨年度から使用していた高速度カメラと合わせることで，可変翼の大きな剛体運動と弾性変形を高精度で捉えることが可能となった．

  27. Deployment Simulation Model based on ANCF Plate Element for Next-Generation Aerospace Structures

    大塚 啓介

    提供機関：Society for Promotion of Space Science

    制度名：2017 Financial Support to Attend International Conferences

    研究機関：The American Institute of Aeronautics and Astronautics (AIAA)

    2018年1月 ～ 2018年1月

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    近年の展開型航空宇宙構造物は軽量化とともに大きく柔軟変形するようになってきている．例えば，JAXAが提案しているDESTINYという深宇宙探査衛星は複数のジョイントで結合された薄型ソーラーパネルを宇宙空間で展開する．また，JAXAやNASAが提案している火星探査航空機は飛行中に翼を展開する機構を有している．実験的に宇宙空間や火星空間を模擬することは難しい．そのため，これら次世代航空宇宙構造物が運用時に問題なく展開完了するためには，数値モデルを用いた展開シミュレーションが重要になる． 本研究では，近年注目されている非線形性有限要素法の１つAbsolute Nodal Coordinate Formulation (ANCF)で表現された板要素をこれら次世代宇宙構造物のシミュレーションに適用できるように発展させた．

︎全件表示 ︎最初の5件までを表示

担当経験のある科目(授業) 6

  1. Design and Drawing I　東北大学

  2. 数学物理学演習II　東北大学

  3. Structural Mechanics　東北大学

  4. Introduction to Aerospace Engineering　東北大学

  5. 機械知能・航空実験II　東北大学

  6. 機械知能・航空実験I　東北大学

︎全件表示 ︎最初の5件までを表示

社会貢献活動 3

  1. 茨城県立並木中等教育学校の出前講座

    2023年9月20日 ～

  2. 数理モデルプログラミング

    2022年12月12日 ～

  3. AOBA-Bを利用したカンタンMATLAB並列処理ハンズオンセミナー

    2022年11月16日 ～