Details of the Researcher

PHOTO

Yoshikazu Ohara
Section
Graduate School of Engineering
Job title
Professor
Degree

  • 博士（工学）（東北大学）

  • 修士（工学）（名古屋工業大学）

Committee Memberships 48

  • Symposium on UltraSonic Electronics　Program Committee Member

    2023/06 - Present

  • 2023 International Congress on Ultrasonics (ICU)　International organizing committee & Session organizer

    2022/06 - Present

  • 日本非破壊検査協会　評議員

    2022/06 - Present

  • Academia NDT International　Council member (co-opted member)

    2021/12 - Present

  • Academia NDT International　Full member

    2020/12 - Present

  • 日本非破壊検査協会 超音波部門　幹事

    2020/04 - Present

  • 20th World Conference on Non-Destructive Testing (WCNDT2020)　Scientific committee

    2019/01 - Present

  • 日本非破壊検査協会・学術委員会　委員

    2016/06 - Present

  • 5th Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan　Co-organizer of special session of signal processing in nonlinear acoustics

    2016/03 - Present

  • 5th Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan　Co-organizer of special session of nonclassical nonlinear acoustics of solids

    2016/03 - Present

  • Symposium on UltraSonic Electronics　Organizing Committee Member

    2011/04 - 2023/06

  • JSNDI workshop of emerging technologies of advanced ultrasonic measurement　Chair

    2020/06 - 2022/06

  • 日本非破壊検査協会 ICTを活用した超音波による非破壊評価技術研究委員会　幹事

    2018/06 - 2020/06

  • 日本非破壊検査協会 超音波計測に関する萌芽技術研究会　幹事

    2018/06 - 2020/06

  • 2019 International Congress on Ultrasonics (ICU2019)　Scientific committee & Session organizer

    2018/10 - 2019/09

  • JSNDI workshop of nondestructive measurement technologies of nonlinear phenomena　Chair

    2016/06 - 2018/06

  • 日本非破壊検査協会・学術委員会　委員

    2016/06 - 2018/06

  • 日本非破壊検査協会 超音波による非接触材料評価研究会　委員

    2016/06 - 2018/06

  • 5th Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan　Co-organizer of special session of signal processing in nonlinear acoustics

    2016/03 - 2016/12

  • 5th Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan　Co-organizer of special session of nonclassical nonlinear acoustics of solids

    2016/03 - 2016/12

  • 日本非破壊検査協会「非線形現象を利用した非破壊評価研究会」　幹事

    2014/05 - 2016/06

  • 日本非破壊検査協会「超音波による非接触非破壊計測・先進評価技術研究会」　委員

    2014/05 - 2016/06

  • 日本非破壊検査協会「非線形現象を利用した非破壊評価研究会」　幹事

    2014/05 - 2016/06

  • 日本非破壊検査協会「超音波による非接触非破壊計測・先進評価技術研究会」　委員

    2014/05 - 2016/06

  • 11th European Conference on Non-Destructive Testing (ECNDT 2014)　Scientific committee

    2013/07 - 2014/11

  • 3rd International Symposium on Lasr Ultrasonic and Advanced Sensing（LU2013)　Scientific committee

    2011/04 - 2014/06

  • 日本非破壊検査協会「非線形超音波による非破壊評価の高度化研究会」　幹事

    2012/05 - 2014/05

  • 日本非破壊検査協会「超音波による非接触センシング・先進評価技術研究会」　委員

    2012/05 - 2014/04

  • 高経年化技術評価高度化事業 疲労割れ非破壊評価の高信頼化検討会　委員

    2013/07 - 2014/03

  • 高経年化技術評価高度化事業 疲労割れ非破壊評価高信頼化検討会　委員

    2012/05 - 2013/03

  • 高経年化技術評価高度化事業 減肉モニタリング予測・監視融合検討会　委員

    2012/05 - 2013/03

  • 日本非破壊検査協会「非線形超音波の基礎と応用に関する研究会」　幹事

    2010/05 - 2012/05

  • 日本非破壊検査協会「超音波による非接触非破壊評価研究会」　委員

    2010/05 - 2012/05

  • 日本非破壊検査協会「非線形超音波の基礎と応用に関する研究会」　幹事

    2010/05 - 2012/05

  • 日本非破壊検査協会「超音波による非接触非破壊評価研究会」　委員

    2010/05 - 2012/05

  • 高経年化技術評価高度化事業 環境助長割れの非破壊評価の高度化検討会　委員

    2011/10 - 2012/02

  • 高経年化技術評価高度化事業 減肉モニタリングによる予測・監視融合の評価手法の検討会　委員

    2011/10 - 2012/02

  • 高経年化対策強化基盤整備事業 東北・北海道クラスター 状態監視保全技術検討会　委員

    2010/07 - 2011/03

  • 高経年化対策強化基盤整備事業 東北・北海道クラスター 応力腐食割れ技術検討会　委員

    2010/07 - 2011/03

  • 日本非破壊検査協会「非線形超音波研究会」　委員

    2008/05 - 2010/05

  • 日本非破壊検査協会「レーザ超音波・先端検査計測技術研究会」　委員

    2008/05 - 2010/05

  • 超音波エレクトロニクスの基礎と応用に関するシンポジウムUSE2010　実行委員

    2009/11 - 2010/03

  • 超音波エレクトロニクスの基礎と応用に関するシンポジウムUSE2010　実行委員

    2009/11 - 2010/03

  • 高経年化対策強化基盤整備事業 東北・北海道クラスター 応力腐食割れ技術検討会　委員

    2009/07 - 2010/03

  • 高経年化対策強化基盤整備事業 東北・北海道クラスター 状態監視保全技術検討会　委員

    2009/07 - 2010/03

  • 超音波エレクトロニクスの基礎と応用に関するシンポジウムUSE2009　実行委員

    2008/11 - 2009/11

  • 日本非破壊検査協会「非線形現象を利用した非破壊検査・材料評価研究会」　委員

    2006/05 - 2008/05

  • ASA (Acoustical Society of America) Fall Meeting　Session organizer

    2019/12 -

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Professional Memberships 7

  • Academia NDT International

  • 非線形音響研究会

  • 電子情報通信学会

  • 日本金属学会

  • IEEE

  • 応用物理学会

  • 日本非破壊検査協会

︎Show all ︎Show first 5

Research Interests 3

  • material evaluation

  • nonlinear dynamics

  • Ultrasonic measurement (nonlinear ultrasound)

Research Areas 1

  • Nanotechnology/Materials / Material fabrication and microstructure control /

Awards 21

  1. Meritorious Award

    2023/03　The Japan Institute of Metals and Materials　Development of innovative ultrasonic phased-array imaging methods for accurate crack sizing

  2. Best Paper Award of the 42nd Symposium on Ultrasonic Electronics

    2022/11　Symposium on Ultrasonic Electronics　High-Resolution 3D Phased-Array Imaging of Fatigue Cracks Using Piezoelectric and Laser Ultrasonic System (PLUS)

  3. 一般財団法人 みやぎ産業科学振興基金 研究奨励賞

    2021/05　一般財団法人 みやぎ産業科学振興基金　革新的3次元超音波映像法の開発

  4. Full member of Academia NDT International

    2020/12　Academia NDT International

  5. The 17th Murakami Incentive Award of the Japan Institute of Metals and Materials

    2020/09　The Japan Institute of Metals and Materials　Development of Nonlinear Ultrasonic Phased Array for the Accurate Measurement of Closed Cracks

  6. The 40th Honda Memorial Incentive Award

    2019/05　The Honda Memorial Foundation

  7. The 17th Intelligent Cosmos Incentive Award

    2018/05　Intelligent Cosmos Academic Foundation

  8. Special Education Award

    2018/03　Graduate School of Engineering, Tohoku University

  9. Best Paper Award of the 34th Symposium on Ultrasonic Electronics

    2014/12　The 34th Symposium on Ultrasonic Electronics

  10. The 54th Harada Young Research Award

    2014/07　The Honda Memorial Foundation

  11. The 23rd Young Researcher Award of the Japan Institute of Metals and Materials

    2013/09　The Japan Institute of Metals and Materials

  12. The 60th Anniversary Most Excellent Paper Award of the Japan Society for Non-destructive Inspection

    2012/10　The Japan Society for Non-destructive Inspection

  13. Best Paper Award of The Japan Society of Applied Physics. (Japanese Journal of Applied Physics)

    2010/09　The Japan Society of Applied Physics

  14. Symposium on Ultrasonic Electronics: Best Paper Award

    2009/11　The 29th Symposium on Ultrasonic Electronics

  15. The 19th Incentive Award from Tokin Foundation for Advancement of Science and Technology

    2009/03　Tokin Foundation for Advancement of Science and Technology

  16. The 14th Incentive Award from Aoba Foundation for the Promotion of Engineering

    2009/01　Aoba Foundaition for the Promotion of Engineering

  17. Incentive Award for Excellent Presentation from the Japan Society of Applied Physics

    2008/09　The Japan Society of Applied Physics

  18. The 29th Incentive Award from the Japan Society for Non-Destructive Inspection

    2008/05　The Japan Society for Non-destructive Inspection　レーザー干渉計を用いたフェーズドアレイによる非線形超音波映像法

  19. Incentive Award of the 25th Symposium on Ultrasonic Electronics (USE2004)

    2005/11　The 25th Symposium on Ultrasonic Electronics　Effect of Adhesion Force between Crack Planes in Analytical Solution of Nonlinear Contact Vibration

  20. Award for Young Researchers from the Japan Society for Non-Destructive Inspection at Spring Conference

    2004/01　The Japan Society for Non-destructive Inspection

  21. Hatakeyama Award from the Japan Society of Mechanical Engineers

    2002/03　The Japan Society of Mechanical Engineers

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Papers 122

  1. High-resolution 3D ultrasonic imaging using high-frequency piezoelectric transmitter and ultra-multiple laser 2D scanning Peer-reviewed

    Takumi Yamada, Yoshikazu Ohara, Timothy J. Ulrich, Marcel C. Remillieux

    NDT&E International　146　103178-1-103178-7　2024/09

    Publisher: Elsevier BV

    DOI： 10.1016/j.ndteint.2024.103178 　

    ISSN： 0963-8695

  2. Multi-mode 3D ultrasonic phased array imaging method using piezoelectric and laser ultrasonic system (PLUS) Peer-reviewed

    Yoshikazu Ohara, T. J. Ulrich, Marcel C. Remillieux, Kosuke Tsunoda, Takumi Yamada, Toshihiro Tsuji, Tsuyoshi Mihara

    Japanese Journal of Applied Physics　62　(SJ)　SJ1019-1-SJ1019-9　2023/02/20

    Publisher: IOP Publishing

    DOI： 10.35848/1347-4065/acb5fd 　

    ISSN： 0021-4922

    eISSN： 1347-4065

    More details Close

    Abstract As a high-resolution 3D phased-array imaging method, a piezoelectric and laser ultrasonic system (PLUS) was proposed, which is a combination of a piezoelectric transmitter and an ultra-multiple scan of a laser Doppler vibrometer. Thus far, PLUS has used an identical mode for incident and scattered waves. On the other hand, the ultrasonic scattering phenomena can accompany the mode conversion, which may provide further information on defects. In this paper, we propose multi-mode PLUS to enhance its imaging capability and attain more robustness. After describing the principle of multi-mode PLUS, we validated the imaging algorithm and demonstrated the improvement in the image resolution using a dataset of simulated received waves for the longitudinal-wave incidence to scatterers. Furthermore, we experimentally demonstrated the efficacy of multi-mode PLUS in a specimen with branched stress corrosion cracking.

  3. Characterization of fatigue crack of hydrogen-charged austenitic stainless steel by electromagnetic and ultrasonic techniques International-journal Peer-reviewed

    Sho Takeda, Yoshikazu Ohara, Tetsuya Uchimoto, Hirotoshi Enoki, Takashi Iijima, Eri Tokuda, Takumi Yamada, Yuzo Nagatomo

    International Journal of Hydrogen Energy　47　(75)　32223-32234　2022/08

    Publisher: Elsevier BV

    DOI： 10.1016/j.ijhydene.2022.07.105 　

    ISSN： 0360-3199

  4. Exploring 3D elastic-wave scattering at interfaces using high-resolution phased-array system Peer-reviewed

    Yoshikazu Ohara, Marcel C. Remillieux, T. J. Ulrich, Serina Ozawa, Kosuke Tsunoda, Toshihiro Tsuji, Tsuyoshi Mihara

    Scientific Reports　12　(1)　8291-1-8291-11　2022/05/25

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s41598-022-12104-9 　

    eISSN： 2045-2322

    More details Close

    Abstract The elastic-wave scattering at interfaces, such as cracks, is essential for nondestructive inspections, and hence, understanding the phenomenon is crucial. However, the elastic-wave scattering at cracks is very complex in three dimensions since microscopic asperities of crack faces can be multiple scattering sources. We propose a method for exploring 3D elastic-wave scattering based on our previously developed high-resolution 3D phased-array system, the piezoelectric and laser ultrasonic system (PLUS). We describe the principle of PLUS, which combines a piezoelectric transmitter and a 2D mechanical scan of a laser Doppler vibrometer, enabling us to resolve a crack into a collection of scattring sources. Subsequently, we show how the 3D elastic-wave scattering in the vicinity of each response can be extracted. Here, we experimentally applied PLUS to a fatigue-crack specimen. We found that diverse 3D elastic-wave scattering occurred in a manner depending on the responses within the fatigue crack. This is significant because access to such information will be useful for optimizing inspection conditions, designing ultrasonic measurement systems, and characterizing cracks. More importantly, the described methodology is very general and can be applied to not only metals but also other materials such as composites, concrete, and rocks, leading to progress in many fields.

  5. High-Resolution 3D Phased-Array Imaging of Fatigue Cracks Using Piezoelectric and Laser Ultrasonic System (PLUS) Peer-reviewed

    Yoshikazu Ohara, Marcel C. Remillieux, T. J. Ulrich, Serina Ozawa, Kosuke Tsunoda, Toshihiro Tsuji, Tsuyoshi Mihara

    Japanese Journal of Applied Physics　61　(SG)　SG1043-1-SG1043-10　2022/05

    Publisher: IOP Publishing

    DOI： 10.35848/1347-4065/ac48cd 　

    ISSN： 0021-4922

    eISSN： 1347-4065

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    Abstract This paper reports the effectiveness of a novel imaging system, piezoelectric and laser ultrasonic system (PLUS), for the three-dimensional (3D) imaging of fatigue cracks with a high-resolution. The PLUS combines a piezoelectric transmitter and the two-dimensional (2D) mechanical scanning of a laser Doppler vibrometer, enabling the 2D matrix array with an ultra-multiple number of receiving points for 3D phased array imaging. After describing the principle and 3D imaging algorithm of PLUS, we show the fundamental 3D imaging capability of the PLUS in a flat-bottom-hole specimen with varying the number of receiving points under a fixed large receiving aperture. We then demonstrate that the PLUS with 4275 receiving points (i.e. 75 × 57) achieves high-resolution 3D imaging of a fatigue crack with a high signal-to-noise ratio, providing the outline of the fatigue crack geometry. We also discuss the effectiveness of the ultra-multiple receiving points for suppressing grating lobes and random noise.

  6. Dark-Field Ultrasonic Imaging Method Using Mode-Converted Longitudinal Evanescent Field Peer-reviewed

    Yota Oyabu, Yoshikazu Ohara, Toshihiro Tsuji, Tsuyoshi Mihara

    Japanese Journal of Applied Physics　61　(SG)　SG1042-1-SG1042-7　2022/05

    Publisher: IOP Publishing

    DOI： 10.35848/1347-4065/ac4add 　

    ISSN： 0021-4922

    eISSN： 1347-4065

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    Abstract We propose a dark-field evanescent imaging method to visualize surface/subsurface micro defects with a high signal-to-noise ratio (SNR). This method utilizes the mode-converted longitudinal evanescent field (MCLEF) generated at defects by the incidence of a shear (S) wave. When an incident S wave only has the in-plane displacement on the top surface of a specimen, the 2D scan of a laser Doppler vibrometer, that can only measure out-of-plane displacements, can selectively probe the MCLEF with out-of-plane displacements. Note that the MCLEF can be generated even at a defect that is much smaller than the diffraction limit. In this paper, after describing the principle of the proposed method, we prove the concept in a specimen with a hole by finite element (FE) simulation and experiments. Further FE simulations demonstrate its super-resolution imaging capability for holes of different sizes and higher SNR than a conventional method for various defect geometries.

  7. Ultrafast phased-array imaging with pump excitation for closed-crack imaging Peer-reviewed

    Yoshikazu Ohara, Sylvain Haupert, Sinan Li

    Applied Physics Express　14　(12)　126505-1-126505-5　2021/12/03

    Publisher: IOP Publishing

    DOI： 10.35848/1882-0786/ac3d1e 　

    ISSN： 1882-0778

    eISSN： 1882-0786

    More details Close

    <title>Abstract</title> Nondestructive evaluation of closed cracks is one of the most challenging problems in ultrasonic testing. Here, we propose a novel closed-crack imaging technique combining ultrafast phased-array with pump excitation. The pump excitation with kHz frequency can effectively induce the crack opening/closing behaviors since it can generate a large displacement of 1000 nm order. At the same time, ultrafast phased-array imaging, i.e. plane wave imaging, with MHz frequency stroboscopically captures the high-speed crack dynamics induced by pump excitation. We successfully proved the concept in a closed fatigue crack specimen.

  8. High-Selectivity Imaging of the Closed Fatigue Crack due to Thermal Environment Using Surface-Acoustic-Wave Phased Array (SAW PA) Peer-reviewed

    Yoshikazu Ohara, Taro Oshiumi, Xiaoyang Wu, Tetsuya Uchimoto, Toshiyuki Takagi, Toshihiro Tsuji, Tsuyoshi Mihara

    Ultrasonics　119　106629-1-106629-8　2021/10

    Publisher: Elsevier BV

    DOI： 10.1016/j.ultras.2021.106629 　

    ISSN： 0041-624X

  9. Development of Low‐Frequency Phased Array for Imaging Defects in Concrete Structures Peer-reviewed

    Yoshikazu Ohara, Kosuke Kikuchi, Toshihiro Tsuji, Tsuyoshi Mihara

    Sensors　21　7012-1-7012-16　2021/10

  10. Experimental analysis of linear and nonlinear ultrasonic scatterings at closed fatigue crack using fixed-voltage fundamental wave amplitude difference with radarlike display Peer-reviewed

    Yoshikazu Ohara, Taisei Umezaki, Ewen Carcreff, Sylvain Haupert, Toshihiro Tsuji, Tsuyoshi Mihara

    Japanese Journal of Applied Physics　60　(SD)　SDDB01-1-SDDB01-8　2021/07/01

    Publisher: IOP Publishing

    DOI： 10.35848/1347-4065/abe2e7 　

    ISSN： 0021-4922

    eISSN： 1347-4065

  11. Toward an ultra-high resolution phased-array system for 3D ultrasonic imaging of solids Peer-reviewed

    Yoshikazu Ohara, Marcel C. Remillieux, Tomomi Onuma, Kosuke Tsunoda, Toshihiro Tsuji, Tsuyoshi Mihara

    Applied Physics Letters　117　(11)　111902-1-111902-5　2020/09/17

    Publisher: AIP Publishing

    DOI： 10.1063/5.0021282 　

    ISSN： 0003-6951

    eISSN： 1077-3118

  12. Imaging of three-dimensional crack open/closed distribution by nonlinear ultrasonic phased array based on fundamental wave amplitude difference Peer-reviewed

    Yoshikazu Ohara, Hiromichi Nakajima, Sylvain Haupert, Toshihiro Tsuji, Tsuyoshi Mihara

    Japanese Journal of Applied Physics　59　(SK)　SKKB01-SKKB01　2020/07/01

    Publisher: IOP Publishing

    DOI： 10.35848/1347-4065/ab79ea 　

    ISSN： 0021-4922

    eISSN： 1347-4065

  13. Detecting and imaging stress corrosion cracking in stainless steel, with application to inspecting storage canisters for spent nuclear fuel Peer-reviewed

    Marcel C. Remillieux, Djamel Kaoumi, Yoshikazu Ohara, Marcie A. Stuber Geesey, Li Xi, Ryan Schoell, Charles R. Bryan, David G. Enos, Deborah A. Summa, T.J. Ulrich, Brian E. Anderson, Zeev Shayer

    NDT & E International　109　102180-102180　2020/01

    Publisher: Elsevier BV

    DOI： 10.1016/j.ndteint.2019.102180 　

    ISSN： 0963-8695

  14. Nonlinear Nonlinear Surface-Acoustic-Wave Phased Array with Fixed-Voltage Fundamental Wave Amplitude Difference for Imaging Closed Cracks Peer-reviewed

    Yoshikazu Ohara, Hiromichi Nakajima, Toshihiro Tsuji, Tsuyoshi Mihara

    NDT&E International　108　102170-1-102170-10　2019/10

    Publisher: Elsevier BV

    DOI： 10.1016/j.ndteint.2019.102170 　

    ISSN： 0963-8695

  15. Nonlinear Ultrasonic Phased Array with Fixed-Voltage Fundamental Wave Amplitude Difference for High-Selectivity Imaging of Closed Cracks Peer-reviewed

    Yoshikazu Ohara, Hiromichi Nakajima, Sylvain Haupert, Toshihiro Tsuji, Tsuyoshi Mihara

    The Journal of the Acoustical Society of America　146　(1)　266-277　2019/07

    Publisher: Acoustical Society of America (ASA)

    DOI： 10.1121/1.5116017 　

    ISSN： 0001-4966

  16. Multi-Mode Nonlinear Ultrasonic Phased Array for Imaging Closed Cracks Peer-reviewed

    Yoshikazu Ohara, Jack Potter, Hiromichi Nakajima, Toshihiro Tsuji, Tsuyoshi Mihara

    Japanese Journal of Applied Physics　58　(SG)　SGGB06-1-SGGB06-7　2019/06

    Publisher: IOP Publishing

    DOI： 10.7567/1347-4065/ab0adc 　

    ISSN： 0021-4922

    eISSN： 1347-4065

  17. Fundamental Wave Amplitude Differene Imaging for Detection and Characterization of Embedded Cracks Peer-reviewed

    Sylvain Haupert, Yoshikazu Ohara, Ewen Carcreff, Guillaume Renaud

    Ultrasonics　96　132-139　2019/02

    DOI： 10.1016/j.ultras.2019.02.003 　

  18. Dynamic acousto-elastic response of single fatigue cracks with different microstructural features: An experimental investigation Peer-reviewed

    Jiang Jin, Jacques Riviere, Yoshikazu Ohara, Parisa Shokouhi

    Journal of Applied Physics　124　075303-1-075303-14　2018/08

    DOI： 10.1063/1.5036531 　

  19. High-selectivity imaging of closed cracks in a coarse-grained stainless steel by nonlinear ultrasonic phased array Peer-reviewed

    Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka, Toshihiro Tsuji, Tsuyoshi Mihara

    NDT & E INTERNATIONAL　91　139-147　2017/10

    DOI： 10.1016/j.ndteint.2017.07.007 　

    ISSN： 0963-8695

    eISSN： 1879-1174

  20. Ultrasonic phased array with surface acoustic wave for imaging cracks Peer-reviewed

    Yoshikazu Ohara, Taro Oshiumi, Hiromichi Nakajima, Kazushi Yamanaka, Xiaoyang Wu, Tetsuya Uchimoto, Toshiyuki Takagi, Toshihiro Tsuji, Tsuyoshi Mihara

    AIP ADVANCES　7　(6)　065214-1-065214-7　2017/06

    DOI： 10.1063/1.4989725 　

    ISSN： 2158-3226

  21. High-Selectivity Ultrasonic Imaging of Closed Cracks Using Global Preheating and Local Cooling Peer-reviewed

    Yoshikazu Ohara, Koji Takahashi, Kentaro Jinno, Kazushi Yamanaka

    MATERIALS TRANSACTIONS　55　(7)　1003-1010　2014/07

    DOI： 10.2320/matertrans.I-M2014810 　

    ISSN： 1345-9678

    eISSN： 1347-5320

  22. Evaluation of crack closure stress by analyses of ultrasonic phased array images during global preheating and local cooling Peer-reviewed

    Koji Takahashi, Kentaro Jinno, Yoshikazu Ohara, Kazushi Yamanaka

    JAPANESE JOURNAL OF APPLIED PHYSICS　53　(7)　07KC20-1-7　2014/07

    DOI： 10.7567/JJAP.53.07KC20 　

    ISSN： 0021-4922

    eISSN： 1347-4065

  23. Optimized Dynamic Acousto-elasticity Applied to Fatigue Damage and Stress Corrosion Cracking Peer-reviewed

    Sylvain Haupert, Jacques Riviere, Brian Anderson, Yoshikazu Ohara, T. J. Ulrich, Paul Johnson

    JOURNAL OF NONDESTRUCTIVE EVALUATION　33　(2)　226-238　2014/06

    DOI： 10.1007/s10921-014-0231-2 　

    ISSN： 0195-9298

    eISSN： 1573-4862

  24. Dynamic Acousto-Elasticity in a Fatigue-Cracked Sample Peer-reviewed

    J. Riviere, M. C. Remillieux, Y. Ohara, B. E. Anderson, S. Haupert, T. J. Ulrich, P. A. Johnson

    JOURNAL OF NONDESTRUCTIVE EVALUATION　33　(2)　216-225　2014/06

    DOI： 10.1007/s10921-014-0225-0 　

    ISSN： 0195-9298

    eISSN： 1573-4862

  25. High-selectivity imaging of closed cracks using elastic waves with thermal stress induced by global preheating and local cooling Peer-reviewed

    Yoshikazu Ohara, Koji Takahashi, Satoru Murai, Kazushi Yamanaka

    Applied Physics Letters　103　(3)　031917-1-5　2013/07/15

    DOI： 10.1063/1.4816160 　

    ISSN： 0003-6951

  26. Improvement of Closed Crack Selectivity in Nonlinear Ultrasonic Imaging Using Fundamental Wave Amplitude Difference Peer-reviewed

    Masako Ikeuchi, Kentaro Jinno, Yoshikazu Ohara, Kazushi Yamanaka

    JAPANESE JOURNAL OF APPLIED PHYSICS　52　(7)　07HC08-1-5　2013/07

    DOI： 10.7567/JJAP.52.07HC08 　

    ISSN： 0021-4922

    eISSN： 1347-4065

  27. Enhancement of Selectivity in Nonlinear Ultrasonic Imaging of Closed Cracks Using Amplitude Difference Phased Array Peer-reviewed

    Yoshikazu Ohara, Yohei Shintaku, Satoshi Horinouchi, Masako Ikeuchi, Kazushi Yamanaka

    JAPANESE JOURNAL OF APPLIED PHYSICS　51　(7)　07GB15-1-5　2012/07

    DOI： 10.1143/JJAP.51.07GB18 　

    ISSN： 0021-4922

  28. Evaluation of Closed Stress Corrosion Cracks in Ni-Based Alloy Weld Metal Using Subharmonic Phased Array Peer-reviewed

    Satoshi Horinouchi, Masako Ikeuchi, Yohei Shintaku, Yoshikazu Ohara, Kazushi Yamanaka

    JAPANESE JOURNAL OF APPLIED PHYSICS　51　(7)　07GB15-1-5　2012/07

    DOI： 10.1143/JJAP.51.07GB15 　

    ISSN： 0021-4922

  29. Closed Crack Growth Monitoring Using Nonlinear Ultrasonic Imaging Method Peer-reviewed

    Yoshikazu Ohara, Makoto Hashimoto, Satoshi Horinouchi, Yohei Shintaku, Kazushi Yamanaka

    電子情報通信学会論文誌　J94-A　(11)　800-808　2011/11/01

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5707

  30. High-Selectivity Imaging of Closed Cracks in Weld Part of Stainless Steel Using Subharmonic Phased Array with a Single Array Transducer Peer-reviewed

    Yoshikazu Ohara, Satoshi Horinouchi, Yohei Shintaku, Ryo Shibasaki, Yuichi Yamaguchi, Minoru Tagami, Kazushi Yamanaka

    非破壊検査　60　(11)　658-664　2011/11/01

    Publisher: The Japanese Society for Non-Destructive Inspection

    DOI： 10.11396/jjsndi.60.658 　

    ISSN： 0367-5866

    More details Close

    To ensure the safety and reliability of structures such as nuclear power plants, it is necessary to detect closed cracks by nonlinear ultrasonic methods. Among them, the novel imaging method, subharmonic phased array for crack evaluation (SPACE) is a practical solution. SPACE uses a LiNbO3 transmitter and array receiver based on the subharmonic waves and phased array. In this paper, we developed SPACE with a single array transducer applicable to small objects. We imaged a stress corrosion crack (SCC) in a heat affected zone (HAZ) of type 304 stainless steel specimen, formed in high temperature pressurized water to simulate the actual cracks formed in nuclear power plants. As a result, we succeeded in visualizing the closed crack tip in the subharmonic image with high selectivity, although the specimen led to strong linear scattering at the grain boundaries. This result will significantly contribute to improving the safety and reliability of nuclear power plants.

  31. Nonlinear ultrasonic imaging method for closed cracks using subtraction of responses at different external loads Peer-reviewed

    Yoshikazu Ohara, Satoshi Horinouchi, Makoto Hashimoto, Yohei Shintaku, Kazushi Yamanaka

    ULTRASONICS　51　(6)　661-666　2011/08

    DOI： 10.1016/j.ultras.2010.12.010 　

    ISSN： 0041-624X

    eISSN： 1874-9968

  32. Imaging of closed cracks using nonlinear response of elastic waves at subharmonic frequency Peer-reviewed

    Yoshikazu Ohara, Tsuyoshi Mihara, Ryouta Sasaki, Toshihiro Ogata, Setsu Yamamoto, Yuuki Kishimoto, Kazushi Yamanaka

    APPLIED PHYSICS LETTERS　90　(1)　011902-01-03　2007/01

    DOI： 10.1063/1.2426891 　

    ISSN： 0003-6951

  33. Effect of adhesion force between crack planes on subharmonic and DC responses in nonlinear ultrasound Peer-reviewed

    Yoshikazu Ohara, Tsuyoshi Mihara, Kazushi Yamanaka

    Ultrasonics　44　(2)　194-199　2006/02

    DOI： 10.1016/j.ultras.2005.10.006 　

    ISSN： 0041-624X

  34. Low-Frequency 3D Ultrasonic Phased Array Imaging Method Using Ultra-Multiple Laser Scanning for Concrete Inspection Peer-reviewed

    Yuto Fujikawa, T. J. Ulrich, Marcel C. Remillieux, Yoshikazu Ohara

    Proceedings of Symposium on Ultrasonic Electronics　44　3J1-3-1-3J1-3-2　2023/11

  35. Defect Identification by Load-Dependence Nonlinear Ultrasonic Phased Array Peer-reviewed

    Toshiki Yoshikawa, Kentaro Jinno, Taisei Ikemura, Yoshikazu Ohara

    Proceedings of Symposium on Ultrasonic Electronics　44　3P2-17-1-3P2-17-2　2023/11

  36. Utilization of Multiple Modes in High-Frequency 3D Ultrasonic Phased Array Imaging Method (PLUS) Peer-reviewed

    Takumi Yamada, T. J. Ulrich, Marcel C. Remillieux, Yoshikazu Ohara

    Proceedings of Symposium on Ultrasonic Electronics　44　3P2-16-1-3P2-16-2　2023

  37. Fundamental Study of Nondestructive Testing of Inner Surface of Stainless-Steel Tubings by Ball SAW Trace Moisture Sensor Peer-reviewed

    T. Tsuji, H. Fukushi, T. Oizumi, N. Takeda, T. Iwaya, S. Akao, Y. Tsukahara, K. Yamanaka, Y. Ohara, T. Mihara

    Proceedings of Symposium on Ultrasonic Electronics　43　3J1-2-1-3J1-2-2　2022/11

  38. 3D Ultrasonic Imaging of Small Defects Using High-Frequency Piezoelectric Transmitter and Ultra-Multiple Laser 2D Scanning Peer-reviewed

    Takumi Yamada, Yoshikazu Ohara, T. J. Ulrich, Marcel C. Remillieux, Toshihiro Tsuji, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　43　3Pb2-2-1-3Pb2-2-2　2022/11

  39. Fundamental Study on 2D Array Transducer for High-Sensitivity 3D Imaging of Creep Damage Peer-reviewed

    Masateru Endo, Kento Isshikida, Takumi Yamada, Iichiro Aizawa, Toshihiro Tsuji, Yoshikazu Ohara, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　43　2Pa2-6-1-2Pa2-6-2　2022/11

  40. Multi-Mode 3D Ultrasonic Phased Array Imaging Method Using Piezoelectric and Laser Ultrasonic System (PLUS) Peer-reviewed

    Yoshikazu Ohara, T. J. Ulrich, Marcel C. Remillieux, Kosuke Tsunoda, Takumi Yamada, Toshihiro Tsuji, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　43　2Pb2-4-1-2Pb2-4-2　2022/11

  41. Fundamental Study of 2-2 Ceramic-Air Composite Transducers for Air-Coupled Ultrasonic Measurement Peer-reviewed

    Hitoshi Kumagai, Toshihiro Tsuji, Yoshikazu Ohara, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　42　1Pb3-3-1-1Pb3-3-2　2021/10

  42. Proposal of Shear-Wave-Excited Evanescent Super-Resolution Imaging Method for the Detection of Micro Defects and Its Fundamental Study Peer-reviewed

    Yota Oyabu, Yoshikazu Ohara, Toshihiro Tsuji, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　42　1Pa2-7-1-1Pa2-7-2　2021/10

  43. Shortening Interval of Burst Waveform Undersampling Measurement of Ball SAW Sensor for Characterizing Metal Surface Morphology Peer-reviewed

    T. Tsuji, H. Fukushi, T. Oizumi, N. Takeda, T. Iwaya, S. Akao, Y. Tsukahara, K. Yamanaka, Y. Ohara, T. Mihara

    Proceedings of Symposium on Ultrasonic Electronics　42　3J2-3-1-3J2-3-2　2021/10

  44. 3D Ultrasonic Phased-Array Imaging of Fatigue Cracks Using a Piezoelectric and Laser System (PLUS) Peer-reviewed

    Yoshikazu Ohara, Marcel C. Remillieux, T. J. Ulrich, Serina Ozawa, Kosuke Tsunoda, Toshihiro Tsuji, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　42　2Pb2-6-1-2Pb2-6-2　2021/10

  45. Development of Couplant-Free Point-Contact Ultrasonic Probe for Concrete Measurement Peer-reviewed

    Tatsuya Suzuki, Toshihiro Tsuji, Yoshikazu Ohara, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　40　1P2-3-1-1P2-3-2　2019/11

  46. Development of Laminated Lithium Niobate Transducer Available at 500 °C Peer-reviewed

    Satoru Abe, Toshihiro Tsuji, Yoshikazu Ohara, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　40　1P2-2-1-1P2-2-2　2019/11

  47. Imaging of Three-Dimensional Crack Open/Closed Distribution by Nonlinear Ultrasonic Phased Array Based on Fundamental Wave Amplitude Difference Peer-reviewed

    Yoshikazu Ohara, Hiromichi Nakajima, Sylvain Haupert, Toshihiro Tsuji, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　40　2P2-10-1-2P2-10-2　2019/11

  48. Nonlinear imaging of closed cracks by a fundamental wave amplitude difference approach Peer-reviewed

    Ewen Carcreff, Dominique Braconnier, Yoshikazu Ohara, Sylvain Haupert, Guillaume Renaud

    Review of Progress in Quantitative Nondestructive Evaluation (QNDE2019)　46　1234-1-1234-3　2019/07

  49. Multi-Mode Nonlinear Ultrasonic Phased Array for Imaging Closed Cracks Peer-reviewed

    Yoshikazu Ohara, Jack Potter, Hiromichi Nakajima, Toshihiro Tsuji, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　39　2P2-8-1-2P2-8-2　2018/10

  50. Ultrafast Phased Array Imaging with Pump Excitation: an Application to Closed Crack Characterization Peer-reviewed

    Yoshikazu Ohara, Sylvain Haupert, Sinan L

    Proceedings of Symposium on Ultrasonic Electronics　39　3P2-10-1-3P2-10-2　2018/10

  51. Incident-Wave-Amplitude Dependence of Closed Crack Imaging by Nonlinear Ultrasonic Phased Array with Fized-Voltage Amplitude Subtraction Peer-reviewed

    Hiromichi Nakajima, Yoshikazu Ohara, Sylvain Haupert, Toshihiro Tsuji, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　39　1P2-14-1-1P2-14-2　2018/10

  52. Development of Soft PZT Phased Array Transducer for Large Amplitude Incidence Peer-reviewed

    Kosuke Kikuchi, Yoshikazu Ohara, Toshihiro Tsuji, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　39　3P2-2-1-3P2-2-2　2018/10

  53. Multi-Mode Nonlinear Ultrasonic Phased Array for Closed Crack Imaging

    Yoshikazu Ohara, Jack Potter, Sylvain Haupert, Hiromichi Nakajima, Toshihioro Tsuji, Tsuyoshi Mihara

    Proceedings of Meetings on Acoustics (POMA)　34　255001-1-255001-5　2018/10

    DOI： 10.1121/2.0000864 　

  54. Subharmonic phased array for crack evaluation (SPACE)

    Yoshikazu Ohara, Tsuyoshi Mihara, Kazushi Yamanaka

    Nonlinear Ultrasonic and Vibro-Acoustical Techniques for Nondestructive Evaluation　419-469　2018/01/01

    Publisher: Springer International Publishing

    DOI： 10.1007/978-3-319-94476-0_10 　

  55. Development of Hertzian contact ultrasonic probe for couplant-free concrete measurement Peer-reviewed

    Toshilhiro Tsuji, Ryota Ikoma, Yoshikazu Ohara, Tsuyoshi Mihara

    IEEE International Ultrasonics Symposium, IUS　2017/10/31

    Publisher: IEEE Computer Society

    DOI： 10.1109/ULTSYM.2017.8092936 　

    ISSN： 1948-5727 1948-5719

  56. Development of highly efficient piezoelectric gas composite probe for air-coupled ultrasonic testing Peer-reviewed

    Toshihiro Tsuji, Daitaro Kitahara, Yasuhiro Tanaka, Yoshikazu Ohara, Tsuyoshi Mihara

    IEEE International Ultrasonics Symposium, IUS　2017/10/31

    Publisher: IEEE Computer Society

    DOI： 10.1109/ULTSYM.2017.8092260 　

    ISSN： 1948-5727 1948-5719

  57. Imaging of Branched Stress Corrosion Cracks by Subharmonic Phased Array for Crack Evaluation Peer-reviewed

    Yoshikazu Ohara, Kazushi Yamanaka, Sinan Li, Toshihiro Tsuji, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　38　1P2-12-1-1P2-12-2　2017/10

  58. Nonlinear Surface-Acoustic-Wave Phased Array with Fixed-Voltage Amplitude Subtraction Method Peer-reviewed

    Hiromichi Nakajima, Yoshikazu Ohara, Toshihiro Tsuji, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　38　2E1-5-1-2E1-5-2　2017/10

  59. Proposal of Low-Frequency Phased Array for Highly Attenuative Materials and Its Fundamental Study for Large Amplitude Incidence Peer-reviewed

    Kosuke Kikuchi, Yoshikazu Ohara, Toshihiro Tsuji, Tsuyoshi Mihara

    Proceedings of Symposium on Ultrasonic Electronics　38　1P2-11-1-1P2-11-2　2017/10

  60. Imaging of laser excited surface acoustic wave for in-process evaluation of 3D additive manufacturing (AM) process Peer-reviewed

    Harumichi Sato, Hisato Ogiso, Naoko Sato, Toru Shimizu, Shizuka Nakano, Yoshikazu Ohara, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　37　3E1-5-1-3E1-5-2　2016/10

  61. 広域加熱・局所冷却を用いた閉じたき裂のフェーズドアレイ映像化における飽和時間の推定 Peer-reviewed

    高橋恒二, 大町弘毅, 小原良和, 山中一司

    非破壊検査　65　(10)　513-520　2016/10

    DOI： 10.11396/jjsndi.65.513 　

  62. Imaging of Closed Cracks in Coarse-Grained Materials by Nonlinear Ultrasonic Phased Array Peer-reviewed

    Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　36　2P2-7-1-2P2-7-2　2015/11

  63. Laser Ultrasonic Characterization of Additive Manufacturing Objects Fabricated by Powder Bed Fusion Peer-reviewed

    Harumichi Sato, Hisato Ogiso, Naoko Sato, Toru Shimizu, Shizuka Nakano, Yoshikazu Ohara, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　36　3J3-4-1-3J3-4-2　2015/11

  64. Subharmonic phased array for crack evaluation using surface acoustic wave Peer-reviewed

    Akihiro Ouchi, Azusa Sugawara, Yoshikazu Ohara, Kazushi Yamanaka

    JAPANESE JOURNAL OF APPLIED PHYSICS　54　(7)　07HC05-1-6　2015/07

    DOI： 10.7567/JJAP.54.07HC05 　

    ISSN： 0021-4922

    eISSN： 1347-4065

  65. Closed-crack imaging and scattering behavior analysis using confocal subharmonic phased array Peer-reviewed

    Azusa Sugawara, Kentaro Jinno, Yoshikazu Ohara, Kazushi Yamanaka

    JAPANESE JOURNAL OF APPLIED PHYSICS　54　(7)　07HC08-1-8　2015/07

    DOI： 10.7567/JJAP.54.07HC08 　

    ISSN： 0021-4922

    eISSN： 1347-4065

  66. Nonlinear Ultrasonic Phased Array Imaging of Closed Cracks Using Global Preheating and Local Cooling Peer-reviewed

    Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka

    RECENT DEVELOPMENTS IN NONLINEAR ACOUSTICS　1685　080002-1-080002-4　2015

    DOI： 10.1063/1.4934455 　

    ISSN： 0094-243X

  67. Effect of Thermal Conductivity on Phased Array Imaging of Closed Crack by Global Preheating and Local Cooling Peer-reviewed

    Koji TAKAHASHI, Kouki OHMACHI, Kentaro JINNO, Yoshikazu OHARA, Kazushi YAMANAKA

    Proceedings of Symposium on Ultrasonic Electronics　35　443-444　2014/12/03

  68. Subharmonic Phased Array for Crack Evaluation Using Refraction and/or Mode Conversion at an Interface Peer-reviewed

    Akihiro OUCHI, Azusa SUGAWARA, Yoshikazu OHARA, Kazushi YAMANAKA

    Proceedings of Symposium on Ultrasonic Electronics　35　259-260　2014/12/03

  69. Closed-Crack Imaging and Scattering Behavior Analysis Using Confocal Subharmonic Phased Array Peer-reviewed

    Azusa SUGAWARA, Kentaro JINNO, Yoshikazu OHARA, Kazushi YAMANAKA

    Proceedings of Symposium on Ultrasonic Electronics　35　11-12　2014/12/03

  70. Analysis on Nonlinear Ultrasonic Images of Vertical Closed Cracks by Damped Double Node Model Peer-reviewed

    Kentaro Jinno, Azusa Sugawara, Yoshikazu Ohara, Kazushi Yamanaka

    MATERIALS TRANSACTIONS　55　(7)　1017-1023　2014/07

    DOI： 10.2320/matertrans.I-M2014812 　

    ISSN： 1345-9678

    eISSN： 1347-5320

  71. Quantitative Analysis of Nonlinear Ultrasonic Response at Closed Cracks by the Damped Double Node Model Peer-reviewed

    Kentaro Jinno, Azusa Sugawara, Koji Takahashi, Yoshikazu Ohara, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　34　371-372　2013/11

  72. Evaluation of Crack Closure Stress by Damped Double Nodes Analyses of Images Obtained by Global Preheating and Local Cooling Peer-reviewed

    Koji Takahashi, Kentaro Jinno, Yoshikazu Ohara, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　34　91-92　2013/11

  73. Nonlinear Ultrasonic Imaging of Closed Cracks by Load Difference Phased Array with Global Pre-Heating and Local Cooling Peer-reviewed

    Yoshikazu Ohara, Satoru Murai, Kohji Takahashi, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　33　299-300　2012/11

  74. Analysis on Nonlinear Ultrasonic Images of Vertical Closed Cracks by Damped Double Node Model Peer-reviewed

    Kentaro Jinno, Masako Ikeuchi, Akihiro Ouchi, Yoshikazu Ohara, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　33　179-180　2012/11

  75. Improvement of Selectivity of Closed Cracks in Nonlinear Ultrasonic Imaging by Using Amplitude Difference of Fundamental Wave Peer-reviewed

    Masako Ikeuchi, Kentaro Jinno, Yoshikazu Ohara, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　33　327-328　2012/11

  76. Two-Dimensional Analyses of Subharmonic Generation at Closed Cracks by the Damped Double Node Peer-reviewed

    Kazushi Yamanaka, Yoshikazu Ohara, Miyuki Oguma, Yohei Shintaku

    Journal of the Japanese Society for Non-Destructive Inspection　61　(3)　113-121　2012/03/01

    Publisher:

    DOI： 10.11396/jjsndi.61.113 　

    ISSN： 0367-5866

  77. Two Dimensional Model for Subharmonic Generation at Closed Cracks with Damped Double Nodes Peer-reviewed

    Kazushi Yamanaka, Yohei Shintaku, Yoshikazu Ohara

    NONLINEAR ACOUSTICS: STATE-OF-THE-ART AND PERSPECTIVES (ISNA 19)　1474　180-183　2012

    DOI： 10.1063/1.4749326 　

    ISSN： 0094-243X

  78. Formation and Evaluation of Closed Stress Corrosion Cracks in Ni-Based Alloy Weld Metal for Nuclear Power Plants Peer-reviewed

    Yoshikazu Ohara, Yohei Shintaku, Satoshi Horinouchi, Kazushi Yamanaka

    NONLINEAR ACOUSTICS: STATE-OF-THE-ART AND PERSPECTIVES (ISNA 19)　1474　184-187　2012

    DOI： 10.1063/1.4749327 　

    ISSN： 0094-243X

  79. Enhancement of the Selectivity of Closed Cracks in Nonlinear Ultrasonic Imaging Using Amplitude Difference Phased Array

    Yoshikazu Ohara, Masako Ikeuchi, Kentaro Jinno, Akihiro Ouchi, Satoshi Horinouchi, Kazushi Yamanaka

    2012 PROCEEDINGS OF SICE ANNUAL CONFERENCE (SICE)　1177-1180　2012

  80. Evaluation of Closed Stress Corrosion Cracks in Nickel Based Alloy Weld Metal Using Subharmonic Phased Array Peer-reviewed

    Satoshi Horinouchi, Masako Ikeuchi, Yohei Shintaku, Yoshikazu Ohara, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　32　75-76　2011/11

  81. Analyses on Nonlinear Ultrasonic Imaging of Closed Cracks by Damped Double Node Model Peer-reviewed

    Yoshikazu Ohara, Yohei Shintaku, Satoshi Horinouchi, Masako Ikeuchi, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　32　31-32　2011/11

  82. Evaluation of Acoustic Anisotropy to Image Defects in Weld Metal by Ultrasonic Phased Array Peer-reviewed

    Yohei Shintaku, Yoshikazu Ohara, Kazushi Yamanaka

    JAPANESE JOURNAL OF APPLIED PHYSICS　50　(9)　096601-1-7　2011/09

    DOI： 10.1143/JJAP.50.096601 　

    ISSN： 0021-4922

  83. Two-Dimensional Analyses of Subharmonic Generation at Closed Cracks in Nonlinear Ultrasonics Peer-reviewed

    Kazushi Yamanaka, Yoshikazu Ohara, Miyuki Oguma, Yohei Shintaku

    APPLIED PHYSICS EXPRESS　4　(7)　076601-1-3　2011/07

    DOI： 10.1143/APEX.4.076601 　

    ISSN： 1882-0778

  84. Meandering collimated beam of surface acoustic waves on a trigonal crystal ball Peer-reviewed

    Takayuki Yanagisawa, Tsuneo Ohgi, Shingo Akao, Noritaka Nakaso, Yusuke Tsukahara, Yoshikazu Ohara, Toshihiro Tsuji, Kazushi Yamanaka

    APPLIED PHYSICS LETTERS　98　(12)　123508-1-3　2011/03

    DOI： 10.1063/1.3567517 　

    ISSN： 0003-6951

  85. Two-dimensional analysis of subharmonic ultrasound generation at closed cracks by damped double nodes Peer-reviewed

    Kazushi Yamanaka, Yohei Shintaku, Miyuki Oguma, Yoshikazu Ohara

    NDT IN PROGRESS 2011, PROCEEDINGS　327-332　2011

  86. Evaluation of Acoustic Anisotropy to Image Defects in Weld Metal by Ultrasonic Phased Array Peer-reviewed

    Yohei Shintaku, Yoshikazu Ohara, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　31　67-68　2010/12

  87. Measurement of Closed Fatigue Cracks with Nonlinear Ultrasonic Imaging Method Using Subtraction of Responses at Different Loads Peer-reviewed

    Makoto Hashimoto, Satoshi Horinouchi, Yohei Shintaku, Yoshikazu Ohara, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　31　61-62　2010/12

  88. 超音波フェーズドアレイによる溶接金属中の欠陥映像化のための音響異方性の解析

    新宅洋平, 小原良和, 山中一司

    電子情報通信学会技術研究報告　US2010-67　105-110　2010/09

  89. Fundamental Study on Nonlinear Ultrasonic Imaging Method for Closed Cracks Using Subtraction of Responses at Different External Loads

    Yoshikazu Ohara, Yohei Shintaku, Makoto Hashimoto, Satoshi Horinouchi, Kazushi Yamanaka

    Proceedings of 20th International Congress on Acoustics,ICA 2010　254-1-5　2010/08

  90. Evaluation of stress corrosion cracks in metals by linear and nonlinear ultrasound

    Yohei Shintaku, Yoshikazu Ohara, Makoto Hashimoto, Satoshi Horinouchi, Kazushi Yamanaka

    Proceedings of 20th International Congress on Acoustics,ICA 2010　473-1-4　2010/08

  91. サブハーモニック超音波フェーズドアレイSPACEを用いた閉じたき裂の映像化

    小原良和, 新宅洋平, 橋本真琴, 堀之内聡, 山中一司

    電子情報通信学会技術研究報告　US2010　(2)　5-10　2010/04

  92. MONITORING GROWTH OF CLOSED FATIGUE CRACK USING SUBHARMONIC PHASED ARRAY Peer-reviewed

    Y. Ohara, H. Endo, M. Hashimoto, Y. Shintaku, K. Yamanaka

    REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 29A AND 29B　1211　903-909　2010

    DOI： 10.1063/1.3362519 　

    ISSN： 0094-243X

  93. Ultrasonic imaging of stress corrosion crack formed in high temperature pressurized water using subharmonic phased array Peer-reviewed

    Yoshikazu Ohara, Yohei Shintaku, Satoshi Horinouchi, Makoto Hashimoto, Yuichi Yamaguchi, Minoru Tagami, Kazushi Yamanaka

    Proceedings of Meetings on Acoustics　10　045007-1-8　2010

    DOI： 10.1121/1.3533836 　

    ISSN： 1939-800X

  94. Nonlinear Ultrasonic Imaging of Closed Cracks Using Subtraction of Responses at Different Loads Peer-reviewed

    Makoto Hashimoto, Yoshikazu Ohara, Hiroaki Endo, Yohei Shintaku, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　30　69-70　2009/11

  95. Observation of closed crack distribution by steering intense ultrasound and with shoe to house transmitter and receiver Peer-reviewed

    Yohei Shintaku, Yoshikazu Ohara, Hiroaki Endo, Makoto Hashimoto, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　30　251-252　2009/11

  96. Improvement of Ball Surface Acoustic Wave Device with Orientation and Thickness Optimization of Interdigital Electrode. Peer-reviewed

    柳沢恭行, 大木恒郎, 赤尾慎吾, 中曽教尊, 小原良和, 山中一司

    Proceedings of Symposium on Ultrasonic Electronics　30　597-598　2009/11

  97. Ultrasonic Measurement of Closed Stress Corrosion Crack Depth Using Subharmonic Phased Array Peer-reviewed

    Yoshikazu Ohara, Hiroaki Endo, Tsuyoshi Mihara, Kazushi Yamanaka

    JAPANESE JOURNAL OF APPLIED PHYSICS　48　(7)　07GD01　2009/07

    DOI： 10.1143/JJAP.48.07GD01 　

    ISSN： 0021-4922

  98. SELECTIVITY ENHANCEMENT OF SUBHARMONIC PHASED ARRAY FOR CRACK EVALUATION (SPACE) Peer-reviewed

    Kazushi Yamanaka, Yoshikazu Ohara

    REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 28A AND 28B　1096　824-831　2009

    DOI： 10.1063/1.3114342 　

    ISSN： 0094-243X

  99. Erratum: Ultrasonic evaluation of closed cracks using subharmonic phased array (Japanese Journal of Applied Physics (2008) 47 (3908)) Peer-reviewed

    Yoshikazu Ohara, Setsu Yamamoto, Tsuyoshi Mihara, Kazushi Yamanaka

    Japanese Journal of Applied Physics　47　(12)　9018　2008/12/19

    DOI： 10.1143/JJAP.47.9018 　

    ISSN： 0021-4922 1347-4065

  100. Nondestructive Evaluation of Closed Cracks Using Nonlinearity of Ultrasound in Solid Invited Peer-reviewed

    Yoshikazu Ohara, Kazushi Yamanaka

    電子情報通信学会論文誌A　J91-A　(12)　1116-1124　2008/12

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5707

  101. Ultrasonic Measurement of Closed Stress Corrosion Crack Depth Using Subharmonic Phased Array Peer-reviewed

    Yoshikazu Ohara, Hiroaki Endo, Tsuyoshi Mihara, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　29　351-352　2008/11

  102. Visualization of elastic waves by photorefractive imaging method Peer-reviewed

    Takahiro Miura, Makoto Ochiai, Yoshikazu Ohara, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　29　375-376　2008/11

  103. Ultrasonic Evaluation of Closed Cracks Using Subharmonic Phased Array Peer-reviewed

    Yoshikazu Ohara, Setsu Yamamoto, Tsuyoshi Mihara, Kazushi Yamanaka

    JAPANESE JOURNAL OF APPLIED PHYSICS　47　(5)　3908-3915　2008/05

    DOI： 10.1143/JJAP.47.3908 　

    ISSN： 0021-4922

  104. Application of Laser Interferometer to Subharmonic Phased Array for Crack Evaluation (SPACE) Peer-reviewed

    Setsu YAMAMOTO, Yoshikazu OHARA, Tsuyoshi MIHARA, Kazushi YAMANAKA

    非破壊検査　57　(4)　198-203　2008/04

    Publisher:

    DOI： 10.11396/jjsndi.57.198 　

    ISSN： 0367-5866

  105. Development of nonlinear ultrasound system using PMN-PT piezoelectric crystal Peer-reviewed

    T. Mihara, Y. Ohara, K. Yamanaka

    American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP　5　161-164　2008

    DOI： 10.1115/PVP2008-61251 　

    ISSN： 0277-027X

  106. Accurate measurement of closed cracks using subharmonic phased array Peer-reviewed

    Yoshikazu Ohara, Setsu Yamamoto, Hiroaki Endo, Tsuyoshi Mihara, Kazushi Yamanaka

    NONLINEAR ACOUSTICS FUNDAMENTALS AND APPLICATIONS　1022　557-+　2008

    ISSN： 0094-243X

  107. Analysis of subharmonic phased array for crack evaluation (SPACE) using elastic-body-oscillator model Peer-reviewed

    Kazushi Yamanaka, Yoshikazu Ohara, Setsu Yamamoto, Hiroaki Endo

    NONLINEAR ACOUSTICS FUNDAMENTALS AND APPLICATIONS　1022　577-580　2008

    ISSN： 0094-243X

  108. Ultrasonic Evaluation of Closed Cracks Using Subharmonic Phased Array Peer-reviewed

    Yoshikazu OHARA, Setsu YAMAMOTO, Tsuyoshi MIHARA, Kazushi YAMANAKA

    Proceedings of Symposium on Ultrasonic Electronics　28　189-190　2007/11

  109. Optimization of input amplitude for closed-crack imaging by nonlinear response of acoustic waves Peer-reviewed

    Yoshikazu Ohara, Setsu Yamamoto, Tsuyoshi Mihara, Kazushi Yamanaka

    Proceedings of Symposium on Ultrasonic Electronics　27　423-424　2006/11

  110. Time domain analysis of subharmonic ultrasound for practical crack sizing Peer-reviewed

    K Yamanaka, R Sasaki, T Ogata, Y Ohara, T Mihara

    REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 25A AND 25B　820　283-290　2006

    DOI： 10.1063/1.2184541 　

    ISSN： 0094-243X

  111. Evaluation of Closed Cracks by Nonlinear Ultrasonic Phased Array Peer-reviewed

    Yoshikazu OHARA, Ryouta SASAKI, Toshihiro OGATA, Tsuyoshi MIHARA, Kazushi YAMANAKA

    Proceedings of Symposium on Ultrasonic Electronics　26　319-320　2005/11

  112. Development of Nonlinear Ultrasonic Phased Array for Evaluating Closed Cracks Peer-reviewed

    Yoshikazu OHARA, Ryouta SASAKI, Toshihiro OGATA, Tsuyoshi MIHARA, Kazushi YAMANAKA

    IEICE　47　19-24　2005/09

  113. A Nonlinear Ultrasonic Imaging System for Detecting Minute Damage and Defects of nm Gaps in Industrial Materials Peer-reviewed

    Koichiro KAWASHIMA, Morimasa MURASE, Yoshikazu OHARA, Ryuzo YAMADA, Masamichi MATUSHIMA, Mitsuyoshi UEMATSU, Fumio FUJITA, Takekazu MIYA

    非破壊検査　54　(9)　509-514　2005/09

    Publisher: The Japanese Society for Non-Destructive Inspection

    DOI： 10.11396/jjsndi.54.509 　

    ISSN： 0367-5866

    More details Close

    A nonlinear ultrasonic imaging system is developed for detecting and imaging of minute damage and defects of nm gaps in industrial materials, which are undetectable by conventional ultrasonic testing. A high powered pulser to excite large amplitude incident waves and high pass or band pass filters to extract the 2nd harmonic are combined with the conventional ultrasonic imaging system. The system is applied to visualize fiber/matrix debonding or matrix crackings in CFRP or FRM laminated plates. It also visualizes anomalous substructures in amorphous diffusion bonded interfaces. This system is also useful for detecting semi-closed cracks with an opening of nm order.

  114. Simulation and analysis of subharmonics and tail effect for ultrasonic nondestructive evaluation of closed cracks Peer-reviewed

    R Sasaki, T Ogata, Y Ohara, T Mihara, K Yamanaka

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS　44　(6B)　4389-4393　2005/06

    DOI： 10.1143/JJAP.44.4389 　

    ISSN： 0021-4922

  115. Imaging of Closed Crack by Nonlinear Ultrasound Measurement with Phased Array Transducer as a Receiver

    Yoshikazu OHARA, Tsuyoshi MIHARA, Kazushi YAMANAKA

    Proceedings of the Third US-Japan Symposium on Advancing Applications and Capabilities in NDE　229-235　2005/06

  116. Fatigue Crack Analysis Using Noninear Ultrasound

    Tsuyoshi MIHARA, Ryouta Sasaki, Toshihiro OGATA, Yoshikazu OHARA, Kazushi YAMANAKA

    Proceedings of the Third US-Japan Symposium on Advancing Applications and Capabilities in NDE　223-227　2005/06

  117. Effect of Adhesion Force between Crack Planes in Analytical Solution of Nonlinear Contact Vibration Peer-reviewed

    Yoshikazu OHARA, Tsuyoshi MIHARA, Kazushi YAMANAKA

    Proceedings of Symposium on Ultrasonic Electronics　25　227-228　2004/10

  118. Detection of internal micro defects by nonlinear resonant ultrasonic method using water immersion Peer-reviewed

    Y Ohara, K Kawashima

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS　43　(5B)　3119-3120　2004/05

    DOI： 10.1143/JJAP.43.31.3119 　

    ISSN： 0021-4922

  119. Evaluation of amorphous diffusion bonding by nonlinear ultrasonic method Peer-reviewed

    Y Ohara, K Kawashima, R Yamada, H Horio

    REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 23A AND 23B　23　944-951　2004

    DOI： 10.1063/1.1711720 　

  120. Identification of Sintered Irons with Nonlinear Ultrasonic Method Peer-reviewed

    Yoshikazu OHARA, Koichiro KAWASHIMA, Morimasa MURASE, Norimitsu HIROSE

    Review of Progress in Quantitative Nondestructive Evaluation　22　1257-1264　2003

    DOI： 10.1063/1.1570276 　

  121. Characterization of sintered irons with nonlinear ultrasonic method

    OHARA Yoshikazu, HANAOKA Sanae, KAWASHIMA Koichiro, HIROSE Norimitsu

    Proceedings of the 1992 Annual Meeting of JSME/MMD　2002　513-514　2002

    Publisher: The Japan Society of Mechanical Engineers

    DOI： 10.1299/jsmezairiki.2002.0_513 　

  122. Detection of Semi-Closed Cracks by Nonlinear Ultrasonics Peer-reviewed

    Koichiro KAWASHIMA, Hiroshi FUJITA, Toshiyuki SHIMA, Takeru OKUMURA, Yoshikazu OHARA

    Proceedings of 6th Far-East Conference on Nondestructive Testing　201-206　2002

Show all ︎Show first 5

Misc. 36

  1. き裂の高精度計測のための先進超音波フェーズドアレイ映像法 Invited Peer-reviewed

    小原良和

    ぶれいず　57　(128)　24-30　2023/10

  2. 高精度き裂計測のための先進超音波フェーズドアレイ映像法 Invited

    小原良和

    溶接技術　71　40-45　2023/10

  3. 原理からわかる非破壊検査技術とのその最前線 第2回：超音波試験法 Invited Peer-reviewed

    小原良和

    保全学　21　(3)　45-52　2022/10

  4. 超多点レーザスキャンに基づく高分解能3D超音波フェーズドアレイ映像法PLUS Invited

    小原良和

    検査技術　27　(10)　15-21　2022/10

  5. 横波励起のモード変換縦波エバネッセント場に基づく暗視野映像法 ～高SN比の超解像イメージングを目指して～ Invited

    小原良和, 大藪陽太

    超音波TECHNO　34　(4)　15-21　2022/07

  6. Recent progress on nonlinear ultrasonic phased array of utilizing fundamental waves Invited Peer-reviewed

    Yoshikazu Ohara

    70　(9)　379-385　2021/09

  7. Development of 3D ultrasonic imaging method (PLUS) for internal defects Invited

    Yoshikazu Ohara

    63　(3)　21-24　2021/03

  8. Fundamental Study of Trace Moisture Inverse Gas Chromatography Using Ball Surface Acoustic Wave Sensor

    辻俊宏, 小原良和, 三原毅

    電子情報通信学会技術研究報告(Web)　120　(396(US2020 77-80))　2021

    ISSN： 2432-6380

  9. Nonlinear ultrasonic phased array based on the fundamental wave amplitude difference of utilizing the feature of array transducer Invited

    Yoshikazu Ohara

    Ultrasonic TECHNO　32　(4)　29-35　2020/07

  10. Imaging of branched stress corrosion cracking by multi-mode subharmonic phased array Invited

    Yoshikazu Ohara

    Ultrasonic TECHNO　31　(6)　87-91　2019/11

  11. Development of Air-Coupled Ultrasonic Probe Using Diced Piezoelectric Elements

    Toshihiro Tsuji, Daitaro Kitahara, Yasuhiro Tanaka, Yoshikazu Ohara, Tsuyoshi Mihara

    Ultrasonic TECHNO　30　(4)　90-94　2018/04

  12. Multi-Mode Nonlinear Resonant Ultrasound Spectroscopy

    Yoshikazu Ohara

    Ultrasonic TECHNO　29　(3)　84-89　2017/05

  13. Ultrasonic Phased Array Apparatus for Nondestructive Evaluation

    Yoshikazu Ohara

    The Journal of the Acoustical Society of Japan　73　(7)　426-427　2016/07

    DOI： 10.20697/jasj.72.7_426 　

  14. Nonlinear Ultrasonic Imaging Method for Closed Cracks

    Yoshikazu Ohara

    The Japan Society of Mechanical Engineering　119　92-93　2016/02

  15. Localization of Closed Cracks Using Multi-Mode Nonlinear Resonant Ultrasound Spectroscopy

    Yoshikazu Ohara, Brian Anderson, T. J. Ulrich, Pierre-Yves Le Bas, Paul Johnson, Sylvain Haupert

    Journal of JSNDI　64　(12)　571-578　2015/12/01

    Publisher: 日本非破壊検査協会

    ISSN： 0367-5866

  16. Nonlinear Ultrasonic Measurement with Low Frequency and High Frequency for Closed Cracks

    Yoshikazu Ohara

    The Journal of the Acoustical Society of Japan　71　(12)　682-688　2015/12/01

    Publisher: The Acoustical Society of Japan (ASJ)

    DOI： 10.20697/jasj.71.12_682 　

    ISSN： 0369-4232

  17. Confocal subharmonic phased array for closed-crack imaging over a wide area

    Azusa Sugawara, Kentaro Jinno, Yoshikazu Ohara, Kazushi Yamanaka

    Ultrasonic TECHNO　27　(3-4)　50-55　2015/03

  18. Surface-Acoustic-Wave Array Imaging Method of Subsurface Cracks and Delaminations -Extension to Nonlinear Ultrasonics-

    Kazushi Yamanaka, Hiroshi Yorifuji, Azusa Sugawara, Akihiro Ouchi, Kentaro Jinno, Yoshikazu Ohara

    Ultrasonic TECHNO　26　(3)　65-69　2014/06/01

  19. Development of Nonlinear Ultrasonic Imaging Method for the Accurate Measurement of Closed Cracks

    Yoshikazu Ohara

    Materia Japan　3　(3)　100-103　2014/03

    Publisher: 日本金属学会 ; 1994-

    DOI： 10.2320/materia.53.100 　

    ISSN： 1340-2625

  20. High-Selectivity Imaging of Closed Cracks Using Global Preheating and Local Cooling and Its Analysis

    Yoshikazu Ohara, Koji Takahashi, Kentaro Jinno, Kazushi Yamanaka

    Journal of JSNDI　62　(12)　600-605　2013/12/01

    Publisher: 日本非破壊検査協会

    ISSN： 0367-5866

  21. Improvement of Selectivity of Closed Cracks in Subharmonic Imaging based on Amplitude Difference Method

    Yoshikazu Ohara, Masako Ikeuchi, Kazushi Yamanaka

    Kensa Gijutu　18(3)　(2013)　1-5　2013/03

  22. OS0710 Improvement of subharmonic phased array for evaluation of closed cracks

    OHARA Yoshikazu, HORINOUCHI Satoshi, SHINTAKU Yohei, Jinno Kentaro, IKEUCHI Masako, OHUCHI Akihiro, YAMANAKA Kazushi

    2012　"OS0710-1"-"OS0710-2"　2012/09/22

    Publisher: The Japan Society of Mechanical Engineers

    More details Close

    The novel imaging method, subharmonic phased array for crack evaluation (SPACE) is a practical solution for imaging closed cracks. SPACE uses a LiNbO3 transmitter and array receiver based on the subharmonic waves and phased array. In this paper, we developed SPACE with a single array transducer applicable to small objects. We imaged a stress corrosion crack (SCC) in a heat affected zone (HAZ) of type 304 stainless steel specimen, formed in high temperature pressurized water to simulate the actual cracks formed in nuclear power plants. As a result, we succeeded in visualizing the closed crack tip in the subharmonic image with high selectivity, although the specimen led to strong linear scattering at the grain boundaries. This result will significantly contribute to improving the safety and reliability of nuclear power plants.

  23. OS0711 Two-dimensional analysis of subharmonic generation at closed cracks using damped double node model

    YAMANAKA Kazushi, Jinno Kentaro, SHINTAKU Yohei, HORINOUCHI Satoshi, IKEUCHI Masako, OHUCHI Akihiro, OHARA Yoshikazu

    2012　"OS0711-1"-"OS0711-2"　2012/09/22

    Publisher: The Japan Society of Mechanical Engineers

    More details Close

    Nonlinear ultrasonics plays an important role in detection of closed cracks in critical structures and machines. Though design and operation of nonlinear measurement require realistic modeling and simulation in two dimensions (2D) or in three dimensions (3D), it has not been realized for subharmonics. In this study, we examine the damped double node (DDN) with compression residual stress in the finite difference time domain method. We examine detailed features of reproducing the complete transmission of small amplitude wave and subharmonic generation by large amplitude wave in 2D.

  24. High-Resolution Imaging of Stress Corrosion Cracking Using Single-Array Subharmonic Phased Array

    Yoshikazu Ohara, Kazushi Yamanaka

    Ultrasonic TECHNO　5-6　33-37　2012/06/01

  25. C102 Imaging and Analysis of Closed Stress Corrosion Cracks in Ni-Based Alloy Weld Metal Using Subharmonic Phased Array

    OHARA Yoshikazu, SHINTAKU Yohei, HORINOUCHI Satoshi, YAMANAKA Kazushi

    National Symposium on Power and Energy Systems　2011　(16)　21-22　2011/06/22

    Publisher: The Japan Society of Mechanical Engineers

    More details Close

    Closed stress corrosion cracks (SCCs) in Ni-based alloy weld metal (NBAWM) lead to a problem of underestimation or overlook in ultrasonic inspection, resulting in catastrophic accidents such as radiation leaks. For application of new inspection methods to solve this problem, and for training/education of inspection, fabrication of realistic closed SCC specimens is required, though it takes many years. Here we propose a two-step process to form closed SCCs in NBAWM in relatively short time of several months. This method first forms an open SCC by accelerated chemical methods and then close it by a short time immersion in high temperature pressurized water (HTPW). The crack closure was verified by subharmonic phased array for crack evaluation (SPACE), capable of measuring closed SCC. In addition, we developed an FDTD (finite difference time domain) method with damped double node (DDN) model of closed crack for 2D simulation of subharmonic generation.

  26. High-Sensitivity Imaging of In-Plane 2D Distribution of Closed Cracks Using Nonlinear Ultrasonics

    Yoshikazu Ohara

    Ultrasonic TECHNO　3-4　49-51　2011/03

  27. C207 Ultrasonic Nondestructive Evaluation of Stress Corrosion Cracks in Welded Parts of Ni-Based Alloy

    OHARA Yoshikazu, SHINTAKU Yohei, KURAMAE Ryuichi, ENDO Hiroaki, YAMANAKA Kazushi

    National Symposium on Power and Energy Systems　2010　(15)　337-338　2010/06/20

    Publisher: The Japan Society of Mechanical Engineers

    More details Close

    In atomic power plants, it has been required to develop an accurate nondestructive evaluation method for stress corrosion cracks (SCCs) generated in welded parts of Ni-based alloy. In this paper, we formed SCC in welded metal of Ni-based alloy (Inconel 600) under tetrathionate solution, and imaged them using a method for closed-crack imaging, SPACE (subharmonic phased array for crack evaluation) developed by us. As a result, we found that the SCCs thus formed were dominantly open. Then we accurately measured their depths improving linear ultrasonic phased array. However, in actual plants, some SCCs were underestimated when they were dominantly closed. In future, it is necessary to improve the evaluation method for closed SCCs.

  28. Accurate Measurement of Closed Cracks Using Subharmonic Phased Array for Crack Evaluation (SPACE)

    Yoshikazu Ohara, Kazushi Yamanaka

    Ultrasonic TECHNO　3-4　72-77　2010/03

  29. Improvement of Subharmonic Phased Array for Crack Evaluation (SPACE) with LiNbO3 Single Crystal Array Transmitter

    Yoshikazu Ohara, Hiroaki Endo, Makoto Hashimoto, Yohei Shintaku, Kazushi Yamanaka

    2009 IEEE International Ultrasonic Symposium (IUS)　2009

    DOI： 10.1063/1.3114342 　

  30. Ultrasonic Measurement of Invisible Cracks ~Development of Subharmonic Phased Array for Crack Evaluation (SPACE)~

    Yoshikazu Ohara, Kazushi Yamanaka

    Kensa Gijutu　13　(5)　8-14　2008/05

  31. Development of Ultrasonic Imaging System "SPACE" for Closed Cracks

    Kazushi Yamanaka, Yoshikazu Ohara, Setsu Yamamoto, Tsuyoshi Mihara

    Genshiryoku Eye　53　(11)　38-41　2007/11

    Publisher: 日刊工業出版プロダクション

    ISSN： 1343-3563

  32. Imaging of Cracks Using Nonlinear Ultrasound

    Kazushi Yamanaka, Yoshikazu Ohara, Setsu Yamamoto, Tsuyoshi Mihara

    Journal of JSNDI　56　(6)　280-285　2007/06

    Publisher: 日本非破壊検査協会

    ISSN： 0367-5866

  33. Detection of Micro Damage in Thin Plates Using Nonlinear Ultrasonic Resonant Method

    Yoshikazu Ohara, Morimasa Murase, Koichiro Kawashima

    Ultrasonic TECHNO　3-4　(2)　28-32　2005/03

    Publisher: 日本工業出版

    ISSN： 0916-2410

  34. P1-33 Simulation of subharmonic wave and tail effect for evaluation of closed cracks

    Sasaki Ryouta, Ogata Toshihiro, Ohara Yoshikazu, Mihara Tuyoshi, Yamanaka Kazushi

    Proceedings of Symposium on Ultrasonic Electronics　25　77-78　2004/10/27

    Publisher: Steering committee of symposium on ultrasonic electronics

    ISSN： 1348-8236

  35. 315 Quality assurance technique of diffusion bonded joints by nonlinear ultrasonic measurement

    Yamada Ryuzo, Horio Hirotsugu, Kawashima Koichiro, Murase Morimasa, Ohara Yoshikazu, Miya Takekazu, Fujita Fumio

    Pre-Prints of the National Meeting of JWS　(75)　174-175　2004/08/20

    Publisher: Japan Welding Society

  36. P2-D-21 Nonlinear Resonant Ultrasonic Method in Water

    Ohara Yoshikazu, Kawashima Koichiro

    Proceedings of Symposium on Ultrasonic Electronics　24　159-160　2003/11/12

    Publisher: Steering committee of symposium on ultrasonic electronics

    ISSN： 1348-8236

Show all ︎Show first 5

Books and Other Publications 3

  1. 超音波による非破壊検査・材料評価技術の進展

    小原良和

    シーエムシー出版　2024/03

    ISBN: 9784781318011

  2. Measurement of Nonlinear Ultrasonic Characteristics

    Kyung-Young Jhang, Cliff J. Lissenden, Igor Solodov, Yoshikazu Ohara, Vitalyi Gusev

    Springer　2020/01

  3. Nonlinear Ultrasonic and Vibro-Acoustical Techniques for Nondestructive Evaluation

    Yoshikazu Ohara, Tsuyoshi Mihara, Kazushi Yamanaka

    Springer　2018/10

Presentations 189

  1. Frontiers of ultrasonic phased array for accurate crack imaging Invited

    Yoshikazu Ohara

    Seminar at Texas A&M University　2024/08/15

  2. Frontiers of ultrasonic phased array for accurate crack imaging Invited

    Yoshikazu Ohara

    Seminar at Los Alamos National Laboratory　2024/08/09

  3. 「計測」の革新が切り拓く持続可能な社会

    小原良和

    東北大学工学部オープンキャンパス工学部模擬講義　2024/07/30

  4. 最先端超音波を駆使した3D欠陥可視化技術創成

    小原良和

    JST創発的研究支援事業 自発的融合の場「マルチフィジックス現象のモデリングとシミュレーション」　2024/07/03

  5. Introduction of Research Activity in Ohara Lab.

    Yoshikazu Ohara

    France-Japan NDT Workshop　2024/06/03

  6. High-Resolution 3D Phased-Array Imaging Using 1024-Element 2D Matrix Array Transducers

    Yoshikazu Ohara, Sinan Li, Takumi Yamada, Yuto Fujikawa, Marcel C. Remillieux, T. J. Ulrich

    20th World Conference on Nondestructive Testing (WCNDT)　2024/05/27

  7. Nonlinear Ultrasonic Phased Array for Closed Cracks

    Yoshikazu Ohara, Sinan Li, Toshiki Yoshikawa, Yoshiaki Ishizuka, Sylvain Hauper, Ewen Carcreff

    20th World Conference on Nondestructive Testing (WCNDT)　2024/05/28

  8. Recent Progress on Nonlinear Ultrasonic Phased Array for Closed-Crack Imaging Invited

    Yoshikazu Ohara

    AOUCSTICS 2023 Sydney　2023/12/04

  9. 最先端超音波を駆使した3D欠陥可視化技術創成

    小原良和

    JST創発 自発的融合の場「（モノの）破壊の先を考える」　2023/11/29

  10. 高精度非破壊計測を実現する先進超音波フェーズドアレイ映像法 Invited

    小原良和

    第124回界面接合研究委員会・2023年度第2回日本溶接協会先端材料接合委員会 合同委員会　2023/10/20

  11. 3D Ultrasonic Phased-Array Imaging for Various NDE Applications

    Yoshikazu Ohara, Takumi Yamada, Yuto Fujikawa, Sinan Li, T. J. Ulrich, Marcel Remilleux

    2023 International Congress on Ultrasonics (ICU)　2023/09/20

  12. Development of 1024-element 2D matrix array transducer for high-resolution 3D phased-array imaging in NDE Applications

    Yoshikazu Ohara, Sinan Li, Takumi Yamada, T. J. Ulrich, Marcel C. Remillieux, Toshihiro Tsuji, Tsuyoshi Mihara

    13th European Conference on Non-Destructive Testing (13th ECNDT)　2023/07/06

  13. 高精度き裂計測のための先進超音波フェーズドアレイ映像法の開発 Invited

    小原良和

    2023年度 非破壊検査総合シンポジウム　2023/06/07

  14. 高精度き裂計測のための先進超音波フェーズドアレイ映像法 Invited

    小原良和

    日本金属学会 2023年春季（第172回）講演大会　2023/03/08

  15. 超音波非破壊検査技術の最前線 Invited

    小原良和

    第22回ADSTEFANユーザ会　2022/12/02

  16. Multi-Mode 3D Ultrasonic Phased Array Imaging Method Using Piezoelectric and Laser Ultrasonic System (PLUS)

    Yoshikazu Ohara, T. J. Ulrich, Marcel C. Remillieux, Kosuke Tsunoda, Takumi Yamada, Toshihiro Tsuji, Tsuyoshi Mihara

    The 43rd Symposium on UltraSonic Electronics (USE2022)　2022/11/08

  17. Signal and Image Processing 4.0 for Nonlinear NDT

    Serge Dos Santos, Yoshikazu Ohara

    General Assembly of Academia NDT International　2022/10

  18. Development of 1024-Element 2D Matrix Array Transducer Based on Numerical Simulation and Experimental Scattering Analyses for NDE Applications

    Yoshikazu Ohara, Takumi Yamada, Sinan Li, Marcel Remillieux, T. J. Ulrich, Toshihiro Tsuji, Tsuyoshi Mihara

    2022 IEEE International Ultrasonics Symposium　2022/10

  19. High-Resolution 3D Ultrasonic Phased-Array Imaging Using Piezoelectric and Laser Ultrasonic System (PLUS) for Nondestructive Evaluation

    Yoshikazu Ohara, Takumi Yamada, Yuta Kobayashi, Marcel Remillieux, T. J. Ulrich, Toshihiro Tsuji, Tsuyoshi Mihara

    2022 IEEE International Ultrasonics Symposium　2022/10

  20. Recent Progress on Ultrasonic Phased Array Imaging Method for Accurate Measurement of Cracks Invited

    Yoshikazu Ohara

    The 78th Seminar on RIKEN Center for Advanced Photonics　2022/09/16

  21. 超音波による非破壊計測技術の最先端 Invited

    小原良和

    日本鉄鋼協会 計測・制御・システム工学部会若手フォーラム　2022/09/14

  22. 閉じたき裂評価のためのポンプ励起を用いた超高速フェーズドアレイ映像法

    小原良和, Sylvain Haupert, Sinan Li

    非線形音響研究会　2022/07/24

  23. Nonlinear Ultrasonic Phased Array for Closed-Crack Imaging

    Y. Ohara, S. Li, S. Haupert, E. Carcreff, T. Yamada, T. Tsuji, T. Mihara

    22nd International Symposium on Nonlinear Acoustics (22nd ISNA)　2022/07/07

  24. 高精度き裂計測のための最先端非破壊評価技術～超音波フェーズドアレイ映像法の新展開と非接触計測の活用例 Invited

    小原良和

    Polytec社ウェビナー　2021/12/02

  25. 3D Ultrasonic Phased-Array Imaging of Fatigue Cracks Using a Piezoelectric and Laser System (PLUS)

    Yoshikazu Ohara, Marcel C. Remillieux, T. J. Ulrich, Serina Ozawa, Kosuke Tsunoda, Toshihiro Tsuji, Tsuyoshi Mihara

    The 42nd Symposium on UltraSonic Electronics (USE2021)　2021/10/26

  26. 非線形超音波フェーズドアレイ映像法と3Dへの展開

    小原良和

    日本非破壊検査協会 2021年度第1回 先進超音波計測に関する萌芽技術研究会　2021/07/05

  27. 革新的3次元超音波映像法の開発 Invited

    小原良和

    一般財団法人 みやぎ産業科学振興基金 表彰式　2021/05/22

  28. Experimental Analysis of Linear and Nonlinear Ultrasonic Responses at Fatigue Cracks Using Fundamental Wave Amplitude Difference

    Yoshikazu Ohara, Taisei Umezaki, Ewen Carcreff, Sylvain Haupert, Toshihiro Tsuji, Tsuyoshi Mihara

    The 41st Symposium on UltraSonic Electronics (USE2020)　2020/11/26

  29. Nonlinear Ultrasonic Phased Array for Accurate Measurement of Closed Cracks Invited

    Yoshikazu Ohara

    2020/09/17

  30. Imaging of Three-Dimensional Crack Open/Closed Distribution by Nonlinear Ultrasonic Phased Array Based on Fundamental Wave Amplitude Difference

    Yoshikazu Ohara, Hiromichi Nakajima, Sylvain Haupert, Toshihiro Tsuji, Tsuyoshi Mihara

    The 40th Symposium on UltraSonic Electronics (USE2019)　2019/11/26

  31. High-Selectivity Imaging of Fatigue Cracks by Fixed-Voltage Fundamental Wave Amplitude Difference (FAD) International-presentation

    Yoshikazu Ohara, Hiromichi Nakajima, Sylvain Haupert, Toshihiro Tsuji, Tsuyoshi Mihara

    2019 International Congress on Ultrasonics (ICU)　2019/09

  32. Ultrafast Phased Array Imaging with Pump Excitation for Closed Crack Characterization International-presentation

    Yoshikazu Ohara, Sylvain Haupert, Sinan Li

    2019 International Congress on Ultrasonics (ICU)　2019/09

  33. Development of Low-Frequency Phased Array for Highly Attenuative Materials International-presentation

    Yoshikazu Ohara, Kosuke Kikuchi, Toshihiro Tsuji, Tsuyoshi Mihara

    2019 International Congress on Ultrasonics (ICU)　2019/09

  34. Ultrafast Imaging with Pump Excitation for Closed Crack Characterization International-presentation

    Yoshikazu Ohara, Sylvain Haupert, Sinan Li

    The 24th International Conference on Nonlinear Elasticity in Materials (ICNEM)　2019/06

  35. Fixed-Voltage Fundamental Wave Amplitude Difference (FAD) for High-Selectivity Imaging of Closed Cracks International-presentation

    Yoshikazu Ohara, Hiromichi Nakajima, Sylvain Haupert, Toshihiro Tsuji, Tsuyoshi Mihara

    The 24th International Conference on Nonlinear Elasticity in Materials (ICNEM)　2019/06

  36. Nonlinear Ultrasonic Phased Arrayfor Closed-Crack Imaging International-presentation

    Yoshikazu Ohara, Toshihiro Tsuji, Tsuyoshi Mihara

    TU-USTB Joint Workshop　2019/01

  37. Multi-Mode Nonlinear Ultrasonic Phased Array for Imaging Closed Cracks International-presentation

    Yoshikazu Ohara, Jack Potter, Hiromichi Nakajima, Toshihiro Tsuji, Tsuyoshi Mihara

    The 39th Symposium on UltraSonic Electronics (USE2018)　2018/10

  38. 電圧固定振幅差分の非線形超音波フェーズドアレイを用いた閉じたき裂映像化における入射波振幅増大の効果

    小原良和, 中島弘達, Sylvain Haupert, 辻俊宏, 三原毅

    非線形音響研究会　2018/09

  39. 非線形超音波フェーズドアレイ映像法の新展開

    小原良和

    日本非破壊検査協会 超音波計測に関する萌芽技術研究会　2018/09

  40. Multi-Mode Nonlinear Ultrasonic Phased Array for Closed Crack Imaging International-presentation

    Yoshikazu Ohara, Jack Potter, Sylvain Haupert, Hiromichi Nakajima, Toshihiro Tsuji, Tsuyoshi Mihara

    21st International Symposium on Nonlinear Acoustics (ISNA) & The 23rd International Conference on Nonlinear Elasticity in Materials (ICNEM)　2018/07/11

  41. Nonlinear Ultrasonic Phased Array for Imaging Closed Cracks International-presentation

    Yoshikazu Ohara, Toshihiro Tsuji, Tsuyoshi Mihara

    ELyT Workshop 2018　2018/03/07

  42. 非線形超音波フェーズドアレイ映像法を用いた閉じたき裂の非破壊評価

    小原 良和

    （公社）日本鋳造工学会 東北支部 第96回鋳造技術部会　2018/02/22

  43. Nonlinear Ultrasonic Phased Array for Closed Crack Imaging International-presentation

    Yoshikazu Ohara

    2017 International Congress on Ultrasonics (ICU）　2017/12/19

  44. Development of Nonloinear Ultrasonic Phased Array for Closed Crack Imaging International-presentation

    Yoshikazu Ohara, Toshihiro Tsuji, Tsuyoshi Mihara

    The 2nd USTB-TU Joint Research Laboratory Workshop　2017/11/20

  45. Imaging of Branched Stress Corrosion Cracks by Subharmonic Phased Array for Crack Evaluation International-presentation

    Yoshikazu Ohara, Kazushi Yamanaka, Sinan Li, Toshihiro Tsuji, Tsuyoshi Mihara

    The 38th Symposium on Ultrasonic Electronics (USE2017)　2017/10/25

  46. 固定電圧振幅差分を用いた非線形表面波フェーズドアレイ映像法

    小原良和, 中島弘達, 山中一司, 辻俊宏, 三原毅

    日本非破壊検査協会 平成29年度秋季講演大会　2017/10/06

  47. Nonlinear Ultrasonic Phased Array with Surface Acoustic Waves International-presentation

    Yoshikazu Ohara, Hiromichi Nakajima, Kazushi Yamanaka, Toshihiro Tsuji, Tsuyoshi Mihara

    The 44th Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE)　2017/07/16

  48. 固定電圧振幅差分を用いた非線形表面波フェーズドアレイによる閉じたき裂の映像化

    小原良和, 中島弘達, 山中一司, 辻俊宏, 三原毅

    非線形音響研究会　2017/07

  49. 表面波を用いた超音波非破壊計測

    小原良和, 三原毅

    日本材料学会 高温強度部門委員会　2017/05

  50. Nonlinear Ultrasonic Phased Array Using Surface Acoustic Wavs for Crack Evaluation International-presentation

    Yoshikazu Ohara, Hiromichi Nakajima, Kazushi Yamanaka, Toshihiro Tsuji, Tsuyoshi Mihara

    22nd International Conference on Nonlinear Elasticity in Materials (ICNEM 2017)　2017/05

  51. Nonlinear ultrasonic phased array for closed crack imaging International-presentation

    Yoshikazu Ohara, Kazushi Yamanaka, Tsuyoshi Mihara

    5th Joint Meeting of the Acoustical Society of America (ASA) and Acoustical Society of Japan (ASJ)　2016/11

  52. 表面波フェーズドアレイを用いたき裂の映像化

    小原良和, 鴛海太郎, 山中一司, Xiao Wu, 内一哲哉, 高木敏行, 三原毅

    日本非破壊検査協会 平成28年度秋季講演大会　2016/10

  53. Surface-Defect Imaging Using Ultrasonic Phased Array with Surface Acoustic Wave International-presentation

    Yoshikazu Ohara, Taro Oshiumi, Kazushi Yamanaka, Tsuyoshi Mihara

    Asia-Pacific Conference on Fracture and Strength 2016 (APCFS2016)　2016/09

  54. 非線形表面波フェーズドアレイを用いた閉じたき裂の映像化

    非線形音響研究会　2016/07

  55. Phased Array with Surface Acoustic Wave (SAW PA) for Imaging Surface Defects International-presentation

    21st International Conference on Nonlinear Elasticity in Materials (ICNEM 2016)　2016/07

  56. Phased Array with Surface Acoustic Wave (SAW PA) for Screening and Sizing of Surface Defects

    The 43rd Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE)　2016/07

  57. サブハーモニック超音波フェーズドアレイによる閉じたき裂のサイジング

    日本保全学会第13回学術講演会　2016/07

  58. 表面波フェーズドアレイを用いた表面欠陥の広範囲映像化

    日本非破壊検査協会 東北支部 平成28年度 支部会・講演会　2016/04

  59. 広域加熱・局所冷却と超音波フェーズドアレイによる閉じたき裂映像化の選択性向上

    圧電材料・デバイスシンポジウム2016　2016/02

  60. 表面波フェーズドアレイを用いた表面き裂の計測

    小原良和, 中島弘達, 鴛海太郎, 山中一司, Xiaoyang Wu, 内一哲哉, 高木敏行, 辻俊宏, 三原毅

    圧電材料・デバイスシンポジウム2016　2016/02

  61. Nonlinear Ultrasonic Phased Array Imaging Methods for Closed Cracks International-presentation

    Seminar at Seoul National University of Science & Technology (Seoul Tech)　2016/01

  62. Nonlinear Ultrasonic Phased Array Imaging Methods for Closed Cracks

    Seminar at Hanyang University　2016/01

  63. Imaging of Closed Cracks in Coarse-Grained Materials by Nonlinear Ultrasonic Phased Array International-presentation

    The 35th Symposium on Ultrasonic Electronics (USE2015)　2015/11

  64. 閉じたき裂の深さ計測のための非線形超音波映像法

    火力原子力発電協会 東北支部主催 研究発表会　2015/11

  65. High-Selectivity Ultrasonic Phased Array Imaging of Closed Cracks in Coarse-Grained Materials Using Global Preheating and Local Cooling

    日本非破壊検査協会 秋季講演大会　2015/10

  66. 最近の非線形超音波法の研究動向

    平成27年度第2回材料の非線形現象を利用した非破壊評価研究会　2015/09/03

  67. 閉じたき裂の非線形超音波映像法と最近の研究動向

    電力中央研究所セミナー　2015/08/21

  68. Measurement of Crack Length Using Subharmonic Phased Array for Crack Evaluation with Surface Acoustic Wave (SAW SPACE)

    Yoshikazu Ohara, Akihiro Ouchi, Juri Saito, Kazushi Yamanaka

    The 20th International Conference on Nonlinear Elasticity in Materials (ICNEM)　2015/07

  69. Closed-Crack Imaging by Nonlinear Ultrasonic Phased Array with Global Preheating and Local Cooling (GPLC) International-presentation

    Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka

    The 20th International Conference on Nonlinear Elasticity in Materials (ICNEM)　2015/07

  70. Ultrasonic Phased Array Imaging of Closed Cracks Using Global Preheating and Local Cooling (GPLC) International-presentation

    Seminar at Laboratoire d'Imagerie Parametrique, UPMC(Universite Pierre et Marie Curie)　2015/07

  71. Crack Length Measurements by Subharmonic Phased Array for Crack Evaluation with Surface Acoustic Wave with Water Immersion International-presentation

    Yoshikazu Ohara, Akihiro Ouchi, Juri Saito, Kazushi Yamanaka

    The 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE)　2015/07

  72. Nonlinear Ultrasonic Imaging of Closed Cracks in a Coarse Grained Stainless Steel by Global Preheating and Local Cooling International-presentation

    Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka

    The 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE)　2015/07

  73. 閉じたき裂の長さ計測のための表面波を用いたサブハーモニック超音波フェーズドアレイ

    小原良和, 大内彬寛, 菅原あずさ, 齋藤樹里, 山中一司

    非破壊検査総合シンポジウム（＋平成27年度第1回材料の非線形現象を利用した非破壊評価研究会）　2015/06

  74. Nonlinear Ultrasonic Phased Array Imaging of Closed Crack Using Global Preheating and Local Cooling International-presentation

    Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka

    20th International Symposium on Nonlinear Acoustics (ISNA)　2015/06

  75. 広域加熱・局所冷却による閉じたき裂の超音波フェーズドアレイ映像化の定量解析

    高橋恒二, 猪慶弘, 小原良和, 山中一司

    第62回応用物理学会春季講演会　2015/03

  76. 界面での屈折・モード変換を用いたき裂評価のための分調波フェーズドアレイの開発

    大内彬寛, 齋藤樹里, 小原良和, 山中一司

    圧電材料・デバイスシンポジウム2015　2015/02

  77. 非線形現象を利用した非破壊評価の展望と限界

    平成26年度第2回 材料の非線形現象を利用した非破壊評価研究会　2015/01

  78. Localization of Closed Cracks Using Multi-Mode Nonlinear Resonance Ultrasound Spectroscopy International-presentation

    Yoshikazu Ohara, Brian E. Anderson, Sylvain Haupert, T. J. Ulrich, Pierre-Yves Le Bas, Paul A. Johnson

    11th European Conference on Non-Destructive Testing (ECNDT)　2014/10

  79. Estimation of Crack Closure Stress from Ultrasonic Phased Array Images during Global Preheating and Local Cooling (GPLC) International-presentation

    Yoshikazu Ohara, Koji Takahashi, Kentaro Jinno, Kazushi Yamanaka

    11th European Conference on Non-Destructive Testing (ECNDT)　2014/10

  80. 複数モード非線形共鳴超音波スペクトロスコピーを用いた閉じたき裂の位置特定の実験的研究

    小原良和, Brian Anderson, Sylvain Haupert,T. J. Ulrich, P.-Y. Le Bas, P. Johnson

    第75回応用物理学会秋季学術講演会　2014/09

  81. Multi-Mode Nonlinear Resonant Ultrasound Spectroscopy (NRUS) for Localizing Cosed Cracks

    日本非破壊検査協会 平成26年度第1回材料の非線形現象を利用した非破壊評価研究会、超音波による非接触非破壊計測・先進評価技術研究会　2014/07

  82. Experimental Verification of Multi-Mode Nonlinear Resonance Ultrasound Spectroscopy to Localize Closed Cracks International-presentation

    Brain E. Anderson, T. J. Ulrich, Pierre-Yves Le Bas, Paul A. Johnson, Sylvain Haupert

    41st Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE)　2014/07

  83. Developement of Confocal Subharmonic Phased Aray for Crack Evaluation for Closed Crack Imaging and Analyses of Nonlinear Scattering Behaviors International-presentation

    Azusa Sugawara, Kentaro Jinno, Kazushi Yamanaka

    41st Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE)　2014/07

  84. Experimental Verification of Multi-Mode Nnlinear Resonance Ultrasound Spectroscopy (NRUS) for Localizing Closed Cracks International-presentation

    Brian E. Anderson, Sylvain Haupert, T. J. Ulrich, Pierre-Yves Le Bas, Paul A. Johnson

    The 19th International Conference on Nonlinear Elasticity in Materials (XIX ICNEM)　2014/06

  85. Development of Confocal Subharmonic Phased Array for Crack Evaluation (SPACE) for Closed Crack Imaging and Analyses of Nonlinear Scattering Behaviors International-presentation

    Azusa Sugawara, Kentaro Jinno, Kazushi Yamanaka

    The 19th International Conference on Nonlinear Elasticity in Materials (XIX ICNEM)　2014/06

  86. 非線形超音波の基礎と応用 ～閉じたき裂の映像法の開発～

    日本材料学会 高温強度部門委員会 第2期第10回 損傷評価WG　2014/03

  87. 複数モード非線形共鳴超音波スペクトロスコピーを用いた閉じたき裂の位置特定

    B. E. Anderson, T. J. Ulrich, P.-Y. Le Bas, P. Johnson

    日本非破壊検査協会平成25年度秋季大会　2013/11/27

  88. 非線形超音波を用いた構造物の欠陥と経年損傷の評価

    日本非破壊検査協会 シンポジウム 社会インフラのメンテナンスを支える非破壊検査技術　2013/09/30

  89. サブハーモニック超音波フェーズドアレイを用いた閉じたき裂深さの計測精度の向上

    日本金属学会 2013年秋季大会　2013/09

  90. Ultrasonic Imaging of Closed Crack with Thermal Stress Induced by Global Preheating and Local Cooling International-presentation

    Koji Takahashi, Kazushi Yamanaka

    40th Annual Review of Progress in QNDE　2013/07/21

  91. Precise Wall Thinning Measurement in Inaccessible Regions of Pipes Using Ultrasonic Multiple Reflection Method Using a Collimated Beam International-presentation

    Koji Takahashi, Kazushi Yamanaka

    40th Annual Review of Progress in QNDE　2013/07/21

  92. 広域加熱・局所冷却を用いた閉じたき裂の高選択性超音波映像法とき裂閉口応力推定法の検討

    高橋恒二, 神納健太郎, 山中一司

    2013年 非線形音響研究会　2013/07/13

  93. Selectivity Improvement of Closed Cracks in Nonlinear Ultrasonic Images by Using Fundamental Wave International-presentation

    Masako Ikeuchi, Kentaro Jinno, Kazushi Yamanaka

    3rd International Symposium on Laser Ultrasonics and Advanced Sensing　2013/06/25

  94. Nonlinear Ultrasonic Imaging of Closed Cracks Using Thermal Stress Induced by Global Preheating and Local Cooling International-presentation

    Koji Takahashi, Kazushi Yamanaka

    3rd International Symposium on Laser Ultrasonics and Advanced Sensing　2013/06/25

  95. Nonlinear Ultrasonic NDT Research and Applications in Japan International-presentation

    Seminar at Laboratoire d'Imagerie Parametrique, Universite Pierre et Marie Curie(UPMC), Sorbonne University　2013/06/17

  96. Enhancement of Selectivity of Closed Cracks in Nonlinear Ultrasound International-presentation

    Kentaro Jinno, Koji Takahashi, Masako Ikeuchi, Kazushi Yamanaka

    The 18th International Conferrence on Nonlinear Elasticity in Mterials　2013/06/09

  97. T 字管補強板下の減肉の高精度計測のための超音波多重反射法の開発

    高橋恒二, 山中一司

    日本非破壊検査協会 春季講演大会　2013/06/03

  98. 広域加熱・局所冷却による熱応力を用いた閉じたき裂の高選択性映像化

    高橋恒二, 山中一司

    第60回応用物理学会春季学術講演会　2013/03/27

  99. 広域加熱・局所冷却を用いた荷重差分法による閉じたき裂映像化の選択性向上

    高橋恒二, 山中一司

    圧電材料・デバイスシンポジウム2013　2013/01/28

  100. Nonlinear Ultrasonic Imaging of Closed Cracks by Load Difference Phased Array with Global Pre-Heating and Local Cooling International-presentation

    Satoru Murai, Kohji Takahashi, Kazushi Yamanaka

    The 33rd Symposium on Ultrasonic Electronics USE2012　2012/11/13

  101. 振幅差分法を用いた非線形超音波映像法による閉じた応力腐食割れの選択

    高橋恒二, 村井 智, 山中一司

    日本非破壊検査協会平成24年度秋季講演大会　2012/10/22

  102. High-Selectivity Imaging of Closed Cracks by Load Difference Phased Array with Local Cooling International-presentation

    Satoru Murai, Satoshi Horinouchi, Kentaro Jinnou, Masako Ikeuchi, Akihiro Ohuchi, Kazushi Yamanaka

    2012 IEEE International Ultrasonics Symposium　2012/10/07

  103. Nonlinear Ultrasonic NDT Research and Applications in Japan International-presentation

    Seminar at K. U. Leuven Campus Kortrijk　2012/10/05

  104. Enhancement of the Selectivity of Closed Cracks in Nonlinear Ultrasonic Imaging Using Amplitude Difference Phased Array. International-presentation

    SICE Annual Conference 2012　2012/08/20

  105. Analysis on Scattering of Large Amplitude Ultrasound at a Closed Crack by the Damped Double Node (DDN) Model. International-presentation

    39th Annual Review of Progress in Quantitative Nondestructive Evaluation　2012/07/15

  106. Load Difference Phased Array with Local Cooling for High-Selectivity Imaging of Closed Cracks. International-presentation

    39th Annual Review of Progress in Quantitative Nondestructive Evaluation　2012/07/15

  107. High-Selctivity Imaging of Closed Cracks by Nonlinear Ultrasound. International-presentation

    The 17th International Conference on Nonlinear Elasticity in Materials(XVⅡICNEM)　2012/07/01

  108. Formation and evaluation of closed stress corrosion cracks in Ni-based alloy weld metal for nuclear power plants International-presentation

    The 19th International Symposium on Nonlinear Acoustics(ISNA)　2012/05/21

  109. 閉じたき裂の高選択性映像化のための非線形超音波映像法

    日本非破壊検査協会 非線形超音波研究会　2012/03/30

  110. Accurate Measurement of Closed Crack Depths Using Subharmonic Phased Array International-presentation

    European GDR-Workshop on Nonlinearities in Acoustics　2012/03/20

  111. Accurate Measurement of Closed-Crack Depths Using Subharmonic Phased Array International-presentation

    Seminar about Recent Ultrasonic Inspection （at LYON INSA）　2012/03/16

  112. Accurate Measurement of Closed-Crack Depths Using Subharmonic Phased Array International-presentation

    Seminar about Recent Ultrasonic Inspection (at University of Stuttgart)　2012/03/14

  113. Accurate Measurement of Closed Cracks Using Subharmonic Phased Array International-presentation

    Seminar about Recent Ultrasonic Inspection （at CEA）　2012/03/13

  114. Accurate Measurement of Closed Cracks Using Subharmonic Phased Array International-presentation

    Seminar about Recent Ultrasonic Inspection （at CEA）　2012/03/06

  115. Advancend Ultrasonic Measurement for Safe and Secure Society International-presentation

    International Symposium of Materials Integration (GCOE)　2011/12/01

  116. Advanced Ultrasonic Measurement for Safety and Security International-presentation

    International Forum on Mechanoluminescence and Novel Structural Health Diagnosis 2011　2011/11/10

  117. 減衰2重節点を用いた閉口き裂の非線形超音波映像の解析 International-presentation

    第32回 超音波エレクトロニクスの基礎と応用に関するシンポジウム(USE2011)　2011/11/08

  118. Accurate Measurement of Closed Crack Depths Using Subharmonic Phased Array International-presentation

    2011 Fall Conference of Korean Society for Nondestructive Testing (KSNT)　2011/10/27

  119. Accurate Measurement of Closed Cracks Using Subharmonic Phased Array International-presentation

    International Workshop at Korea Research Institute of Standards and Science (KRISS)　2011/10/26

  120. Imaging and Analysis of Closed Strtess Corrosion Cracks Using Subharmonic Phased Array International-presentation

    International Conference on Advanced Technology in Experimental Mechanics 2011 (ATEM'11)　2011/09/19

  121. Accelerated Formatikon of Closed Stress Corrosion Cracks in Ni-Based Alloy Weld Metal and Its evaluation by Subharmonic Phased Array International-presentation

    International Congress on Ultrasonics (ICU)　2011/09

  122. 非線形超音波計測-サブハーモニック（分調）波を用いた映像法SPACEによる閉じた応力腐食割れの映像化

    平成23年度第1回非線形超音波の基礎と応用に関する研究会　2011/08

  123. Two-Step Formation of Closed Stress Corrosion Cracks in Ni-Based Alloy Weld Metal and Its Evaluation by Subharmonic Phased Array International-presentation

    38th Annual Review of Progress in Quantitative Nondestructive Evaluation　2011/07

  124. Development of Subharmonic Phased Array with a Single Array Transducer for Closed Crack Imaging International-presentation

    38th Annual Review of Progress in Quantitative Nondestructive Evaluation　2011/07

  125. Development of Subharmonic Phased Array with a Single Array and 2D Simulation Method for Evaluation of Closed Stress Corrosion Cracks International-presentation

    XVI International Conference on Nonlinear Elasticity in Materials (XVI ICNEM)　2011/06

  126. サブハーモニック超音波フェーズドアレイSPACEによるNi基合金溶接金属中の閉じたき裂の映像化と解析

    日本機械学会 第16回動力・エネルギー技術シンポジウム　2011/06

  127. サブハーモニック超音波フェーズドアレイによる閉じたき裂の映像化と時間領域差分法による解析

    日本非破壊検査協会 平成23年度春季大会　2011/05

  128. サブハーモニック超音波フェーズドアレイによる閉口き裂の映像と解析

    圧電材料・デバイスシンポジウム 2011　2011/02

  129. Ultrasonic Measurement of Closed Stress Corrosion Crack Depth Using Subharmonic Phased Array

    2010年度秋季大会 第71回応用物理学会学術講演会　2010/09/14

  130. 荷重差分を用いた非線形超音波映像法による閉じたき裂の選択性向上

    2010年度秋季大会 第71回応用物理学会学術講演会　2010/09/14

  131. 閉口き裂の非線形超音波解析のための2次元モデル

    2010年度秋季大会 第71回応用物理学会学術講演会　2010/09/14

  132. Fundamental study on nonlinear ultrasonic imaging method for closed cracks using subtraction of responses at different external loads International-presentation

    International Congress on Acoustics 2010　2010/08/23

  133. 閉じたき裂評価のための非線形超音波とSCCへの適用

    日本非破壊検査協会 非線形超音波の基礎と応用に関する研究会・模擬SCC探傷研究委員会　2010/08/05

  134. 荷重依存性を用いた閉じたき裂の非線形超音波映像法の検討

    非線形音響研究会　2010/07/28

  135. Compensation for Beam Deflection in Ultrasonic Phased Array Imaging of Defects in Weld Metal International-presentation

    37th Annual Review of Progress in QNDE　2010/07/18

  136. Phased-Array Imaging Using Subtraction of Nonlinear Ultrasonic Responses at Different External Loads International-presentation

    37th Annual Review of Progress in QNDE　2010/07/18

  137. Ultrasonic Imaging of Stress Corrosion Crack Formed in High Temperature Pressurized Water Using Subharmonic Phased Array for Crack Evaluation (SPACE) International-presentation

    XV International Conference on Nonlinear Elasticity in Materials (15th ICNEM)　2010/07/03

  138. Ni基合金溶接金属中の応力腐食割れの超音波非破壊評価

    日本機械学会 第15回動力・エネルギー技術シンポジウム-動力エネルギーシステム部門20周年，次の20年への新展開-　2010/06

  139. サブハーモニック超音波フェーズドアレイSPACEを用いた閉じたき裂の映像化

    電子情報通信学会研究会 超音波研究会　2010/04

  140. ステンレス鋼の応力腐食割れの超音波計測

    第10回核破砕中性子源材料技術の研究会　2009/12

  141. サブハーモニック超音波フェーズドアレイSPACEを用いた閉じたき裂の高精度計測

    新素材の非破壊評価特別研究委員会ミニシンポジウム　2009/11

  142. Monitoring of Fatigue Damage Using Subharmonic Phased Array for Crack Evaluation (SPACE) International-presentation

    IEEE International Ultrasonics Symposium　2009/09/20

  143. 広い領域の力学的非線形性評価のための送信用LiNbO3単結晶アレイの試作

    2009年秋季 第70回応用物理学会学術講演会　2009/09

  144. 閉じたき裂の超音波映像の荷重依存性に関する基礎的検討

    2009年秋季 第70回応用物理学会学術講演会　2009/09

  145. Monitoring Growth of Closed Fatigue Crack Using Subharmonic Phased Array International-presentation

    36th Annual Review of Progress in Quantitative Nondestructive Evaluation　2009/07

  146. サブハーモニック超音波フェーズドアレイSPACEによるCT疲労き裂の進展モニタリング

    第56回応用物理学関係連合講演会　2009/03

  147. 閉じたき裂の超音波映像の荷重依存性に関する基礎的検討

    2009年秋季 第70回応用物理学会学術講演会　2009/03

  148. 「安全と安心のための先進超音波計測」プロジェクト

    山中一司

    第2回レーザー超音波および先進非接触計測技術研究会　2008/11/14

  149. サブハーモニック超音波フェーズドアレイSPACEによる応力腐食割れの映像化 International-presentation

    遠藤宏明, 三原毅, 山中一司

    第29回超音波エレクトロニクスの基礎と応用に関するシンポジウム（USE2008）　2008/11/11

  150. Ultrasonic Measurement of Closed Stress Corrosion Crack Depth Using Subharmonic Phased Array International-presentation

    Hiroaki Endo, Setsu Yamamoto, Kazushi Yamanaka

    9th International Workshop on Spallation Materials Technology (IWSMT-9)　2008/10/19

  151. 閉じたき裂映像化のための高選択性・高分解能long-burst SPACEに関する基礎的検討

    2008年秋季 第69回応用物理学会学術講演会　2008/09/02

  152. Selectivity Enhancement of Subharmonic Phased Array for Crack Evaluation (SPACE) International-presentation

    35th Annual Review of Progress in Quantitative Nondestructive Evaluation　2008/07/20

  153. Accurate Measurement of Closed Cracks Using Subharmonic Phased Array International-presentation

    18th International Symposium on Nonlinear Acoustics　2008/07

  154. サブハーモニック超音波フェーズドアレイSPACEを用いた応力腐食割れの定量評価

    日本非破壊検査協会 平成20年度春季大会　2008/05

  155. サブハーモニック超音波フェーズドアレイSPACEによる応力腐食割れの計測精度の検討

    2008年春季 第55回応用物理学関係連合講演会　2008/03

  156. サブハーモニック超音波フェーズドアレイSPACEを用いた閉じたき裂の高精度評価

    いわて・みやぎ県際広域連携 ものづくり・ひとづくり交流会　2007/11

  157. Ultrasonic Evaluation of Closed Cracks Using Subharmonic Phased Array International-presentation

    Symposium on Ultrasonic Electronics　2007/11

  158. サブハーモニック超音波フェーズドアレイSPACEにおける閉じたき裂の計測精度の検討

    日本非破壊検査協会 平成19年度秋季大会　2007/09

  159. サブハーモニック超音波フェーズドアレイSPACEによる応力腐食割れの映像化

    2007年秋季 第68回応用物理学会学術講演会　2007/09

  160. 閉じたき裂評価のためのサブハーモニック超音波フェーズドアレイSPACEの開発

    日本非破壊検査協会 界面の健全性評価技術に関する合同ワークショップ　2007/08

  161. Improvement of Subharmonic Phased Array for Crack Evaluation (SPACE) and its Practical Applications International-presentation

    34th Annual Review of Progress in Quantitative Nondestructive Evaluation　2007/07

  162. ICU-Vienna参加報告

    日本非破壊検査協会 非線形現象を利用した非破壊検査・材料評価研究会　2007/07

  163. Subharmonic Ultrasonic Phased Array for Accurate Evaluation of Closed Cracks International-presentation

    The Japan-China Joint Conference on Acoustics JCA 2007　2007/06

  164. 非線形超音波フェーズドアレイによる閉じたき裂の映像化

    日本非破壊検査協会 平成19年度春季大会　2007/05

  165. Accurate Ultrasonic Evaluation of Closed Cracks Using Subharmonic Phased Array International-presentation

    The International Congress on Ultrasonics　2007/04

  166. 非線形超音波画像化システムよる鉄鋼製造プロセスで発生した閉じたき裂の映像化

    2007年春季 第54回応用物理学関係連合講演会　2007/03

  167. 超音波の非線形応答による閉じたき裂画像化のための入射波振幅の最適化 International-presentation

    第27回 超音波エレクトロニクスの基礎と応用に関するシンポジウム　2006/11

  168. Development of Subharmonic Imaging Apparatus for Closed Cracks International-presentation

    Review of Progress in Quantitative Nondestructive Evaluation　2006/07

  169. 閉口き裂を映像化する非線形超音波フェーズドアレイの基礎的検討

    日本保全学会 第三回学術講演会　2006/07

  170. 非線形超音波による閉じたき裂画像化の基礎的検討

    日本非破壊検査協会 春季大会　2006/05

  171. サブハーモニック超音波による閉じたき裂の評価

    圧電材料・デバイスシンポジウム 2006　2006/02

  172. 非線形超音波フェーズドアレイによる閉じたき裂の画像化

    日本非破壊検査協会 秋季大会　2005/11

  173. Evaluation of Closed Cracks by Nonlinear Ultrasonic Phased Array International-presentation

    Symposium on Ultrasonic Electronics　2005/11

  174. 非線形超音波フェーズドアレイによる閉じたき裂の画像化

    電子情報通信学会研究会 超音波研究会　2005/09

  175. Nonlinear Ultrasonic Phased Array for Imaging Closed Cracks by Super- and Subharmonics International-presentation

    IEEE International Ultrasonics Symposium　2005/09

  176. Imaging of Closed Crack by Nonlinear Ultrasound Measurement with Phased Array Transducer as a Receiver International-presentation

    The Third US-Japan Symposium on Advancing Applications and Capabilities in NDE　2005/06

  177. Effect of Adhesion Force between Crack Planes in Analytical Solution of Nonlinear Contact Vibration International-presentation

    Symposium on Ultrasonic Electronics　2004/10

  178. Nondestructive Evaluation of Closed Crack by Nonlinear Ultrasound International-presentation

    国際ワークショップ（東北大、京大、Kaist、K-Jist（韓国）共催）　2004/08

  179. 水浸非線形超音波共鳴法を用いたSiC繊維強化Ti合金複合材料の微視損傷評価

    複合材料の損傷と強度に関する力学的モデル　2004/03

  180. 水浸非線形超音波共鳴法を用いた微視欠陥検出

    第11回 超音波による非破壊評価シンポジウム　2004/01

  181. 水浸非線形超音波共鳴法を用いた微視欠陥の検出

    東海・材料の力学談話会　2003/11

  182. 水浸共鳴法を用いた非線形超音波法

    第24回 超音波エレクトロニクスの基礎と応用に関するシンポジウム　2003/11

  183. Evaluation of Amorphous Diffusion Bonding by Nonlinear Ultrasonic Method International-presentation

    超音波応用会　2003/09

  184. Evaluation of Amorphous Diffusion Bonding by Nonlinear Ultrasonic Method International-presentation

    Review of Progress in Quantitative Nondestructive Evaluation　2003/07

  185. 非線形超音波法を用いた液相拡散接合界面の健全性評価

    日本非破壊検査協会 春季大会　2003/05

  186. 非線形超音波法を用いた焼結鉄の特性評価

    日本機械学会M&M2002　2002/10

  187. Identification of Sintered Irons with Nonlinear Ultrasonic Method International-presentation

    Review of Progress in Quantitative Nondestructive Evaluation　2002/07

  188. 超音波の非線形性を用いた焼結鉄の特性評価

    日本非破壊検査協会 春季大会　2002/05

  189. 超音波の非線形性を用いた焼結鉄の特性評価

    日本非破壊検査協会 新素材の非破壊評価特別研究委員会　2002/03

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Industrial Property Rights 4

  1. 欠陥検査装置、欠陥検査方法、プログラム及び記憶媒体

    山中一司, 小原良和, 永田泰昭

    Property Type: Patent

  2. 超音波を用いる物体検査方法および装置

    川嶋紘一郎, 小原良和

    Property Type: Patent

  3. METHOD FOR IMAGING STRUCTURE DEFECT,DEVICE FOR IMAGING STRUCTURE DEFECT,METHOD FOR IMAGING BUBBLE OR LESION, AND DEVICE FOR IMAGING BUBBLE OR LESION(構造物欠陥の映像化方法、構造物欠陥の映像化装置、気泡や病変部の映像化方法および気泡や病変部の映像化装置)

    Kazushi Yamanaka, Yoshikazu Ohara, Yohei Shintaku

    ZL 2009 8 0128195.5

    Property Type: Patent

  4. METHOD FOR IMAGING A STRUCTURE DEFECT AND DEVICE FOR IMAGING A STRUCTURE DEFECT

    Kazushi Yamanaka, Yoshikazu Ohara, Yohei Shintaku

    特許EP 2 315 020 B1

    Property Type: Patent

Research Projects 18

  1. コンクリート内部損傷の遠隔3D検査を実現するドライアイス衝突式レーザアレイ映像法

    小原 良和

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業 基盤研究(A)

    Category: 基盤研究(A)

    Institution: 東北大学

    2021/04/05 - 2025/03/31

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    大震災・豪雨など自然災害が頻発する昨今、安全・安心な社会の実現は国民最大の関心事だが、社会インフラの安全性保証・長寿命化において、高精度な非破壊評価技術の確立は最重要課題である。しかし、高度経済成長期に建造され経年劣化したトンネル・橋梁・高速道路などのコンクリート構造物は金属よりはるかに不均質・高減衰であり、検査対象領域が膨大、かつ、粗面への対応も求められることから、非破壊計測分野における最難関課題である。そこで本研究では、ドライアイス衝突による高効率の超音波発生技術と粗面・広範囲計測可能な赤外レーザスキャン技術（超多素子レーザ走査アレイ）の融合により、コンクリート内部欠陥を遠隔から3Dで可視化する世界初の高分解能超音波映像法の創出に挑戦する。これにより、内部欠陥の3D形状に基づく新たな効率的維持管理と実構造物の欠陥発生機構解明に新たな道筋を作ることを目的とする。今年度は下記2項目を実施した。 <BR> [1]赤外レーザ走査2Dアレイの試作 赤外光レーザを利用した最新の高強度レーザドップラ振動計を導入する。赤外光は人体（眼）への影響が小さいため、レーザ光強度を一桁上げることができ、本研究で用いる低周波（30～300kHz）でも十分な受信感度を有する。また、特殊な管理区画を設けなくても使用可能という利点も有する。これに、広範囲スキャン装置を融合することで、粗面コンクリートの広範囲計測を実現する赤外レーザ走査2Dアレイを試作した。 [2]コンクリート用3D映像化アルゴリズムの定式化 コンクリートでの3D映像化を成功させるため、対象の音速と幾何学的関係から遅延則を定式化し、適切な周波数を選択可能なバンドパスフィルタとシフト加算波形のRMS（root mean square）値を3D的に抽出するアルゴリズムを定式化した。

  2. モード変換エバネッセント場が切り拓く薄板接合部の超解像可視化技術創成

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory)

    Category: Grant-in-Aid for Challenging Research (Exploratory)

    Institution: Tohoku University

    2022/06 - 2025/03

  3. Ultra-Multiple-Point Laser Scanning 3D Ultrasonic Imaging Method for Challenging to Improve Reliability of Actual Structures and Elucidate Defect Generation Mechanisms

    Ohara Yoshikazu

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Research (Exploratory)

    Institution: Tohoku University

    2019/06/28 - 2022/03/31

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    Cracks in power plants, trains, rockets, and automotive components have complex 3D geometries. If 3D imaging of internal defects in actual structures is achieved, it will enable to ensure the reliability of actual structures based on accurate 3D defect geometry and will also lead to the elucidation of the defect generation mechanism in them. However, ultrasonic imaging methods applicable in the field have been limited to 2D imaging, even with the latest ultrasonic phased array. In this study, we challenged creating a high-resolution 3D ultrasonic imaging method based on ultra-multiple-point laser 2D scan and large-amplitude ultrasonic transmission technology and established the fundamentals for this method.

  4. 最先端超音波を駆使した3D欠陥可視化技術創成

    Offer Organization: JST

    System: 創発的研究支援事業

    Institution: 東北大学

    2021/02 -

  5. Development of nonlinear ultrasonic phased array imaging with surface acoustic wave and thermal stress

    Ohara Yoshikazu

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2015/04/01 - 2018/03/31

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    Accurate measurement of surface crack is very important to ensure the safety and reliability of strategic structures because surface is one of defects-prone areas. However, conventional ultrasonic method may cause underestimation or overlook, since some of them are closed. In this study, we proposed and developed a novel imaging method, nonlinear ultrasonic phased array imaging with surface acoustic wave and thermal stress. It was demonstrated that our proposed technique is very useful in improving the sensitivity of detection of closed surface cracks and in achieving high measurement accuracy of crack length.

  6. Low-Frequency Nonlinear Ultrasonic Imaging Method for Crack Evaluation in Concrete Structures

    OHARA Yoshikazu

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Tohoku University

    2014/04/01 - 2017/03/31

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    Aging infrastructure has been inspected to ensure the safety and reliability, where most infrastructure has been made of concrete. However, it is difficult to inspect such concrete structures by ultrasonics with MHz because it is generally highly attenuative and heterogeneous. In this study, we developed the fundamental techniques to realize low-frequency nonlinear ultrasonic imaging method for the inspection of aging concrete structures. First, we constructed an imaging system that uses contact-type transmitter with a wedge and the laser scanning receiving array. It was demonstrated in the metal and concrete specimens. Furthermore, we fabricated a high-output low-frequency transducers and made a user-friendly imaging program.

  7. Nonlinear laser ultrasonic testing for remote testing of initial material damage and closed cracks

    YAMANAKA Kazushi, OHARA Yoshikazu

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Tohoku University

    2014/04/01 - 2015/03/31

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    For the safety of materials and structures, nonlinear ultrasound testing are highly demanded that enables evaluation of closed cracks. Though laser ultrasound (LU) using pulsed laser generation of ultrasound enabling remote testing is useful, nonlinear testing by LU has not been realized. Therefore, we developed a novel nonlinear LU method in this study where a laser pulse of finite energy is irradiated on the tested object, and image is formed by shift and summation of waveforms detected at different positions. Then we obtain difference of image intensities formed for different laser energy, and evaluate nonlinear response at closed cracks. Then we verified the developed method by performing a damped double node (DDN) model simulation using parameters used in a real LU in-process testing equipment, where a closed crack with 10 MPa closure stress was located near a void. It was shown that the effect of void can be successfully suppressed by the developed method.

  8. Development of high temporal resolution subharmonic phased array and application to online testing of steel pipes

    YAMANAKA Kazushi, TSUJI Toshihiro, OHARA Yoshikazu

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    2012/04/01 - 2015/03/31

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    Since closed cracks are transparent to ultrasound, measurement error in ultrasonic testing is a difficult problem. Since welded steel pipes are widely used in structural components of important facilities, effects of accidents caused by overlook of closed cracks is serious. Therefore, we realized measurement of closed cracks by the subharmonic phased array for crack evaluation (SPACE) in a wide area. By correcting the aberration caused by refraction at water/ steel interface, it enabled large amplitude incident waves to the cracks. Also, we developed surface acoustic wave (SAW) SPACE and fundamental amplitude difference (FAD) method to enhance the temporal resolution, and verified them with standard closed cracks. Then, we implemented those methods in the online testing equipment and verified their performance in real testing condition for production line of pipes.

  9. Three-dimensional nonlinear ultrasonic imaging method of closed cracks by local cooling

    OHARA Yoshikazu

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (A)

    Category: Grant-in-Aid for Young Scientists (A)

    Institution: Tohoku University

    2012/04/01 - 2015/03/31

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    As a method of accurately measuring closed cracks, nonlinear ultrasonic imaging method was developed by combining the phased array and local cooling. First, we succeeded in significantly enhancing the closed-crack opening ability by global preheating and local cooling (GPLC). As the measurement system, we designed and made transducer and phased array apparatus. By applying it to closed cracks in aluminum alloy and stainless steel specimens, which are widely used in infrastructure, we demonstrated that GPLC is very useful in measuring closed cracks. Furthermore, by formulating one-dimensional heat-transfer and thermal stress analyses, we proposed a crack closure stress estimation method and demonstrated it in closed crack specimens.

  10. Closed-crack imaging method, subharmonic phased array for crack evaluation (SPACE) , for curved surfaces

    OHARA Yoshikazu, YAMANAKA Kazushi, TSUJI Toshihiro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Tohoku University

    2012/04/01 - 2014/03/31

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    In the field of nondestructive evaluation, "curved surface" and "closed crack" are two big problems that we need to resolve. Thus far we have developed an closed-crack imaging method, subharmonic phased array for crack evaluation (SPACE). In this study, we propose a new imaging method by combining SPACE and state-of-the-art array transducer, flexible array transducer, which can conform a curved surface. First we formulated an imaging algorithm under a consideration of curvature. We designed and fabricated the flexible array transducer. Furthermore, we measured the sound field due to the flexible array transducer by utilizing the scanning laser interferometer. Thus we demonstrated the fundamental performance of SPACE which can be applied to an arbitrary curved surface.

  11. Development of diagnostic technique for structure filled with liquid metal using acoustic vibration

    WAKUI Takashi, FUTAKAWA Masatoshi, TESHIGAWARA Makoto, NAOE Takashi, SATO Harumichi, YAMANAKA Kazushi, OHARA Yoshikazu, KAWASHIMA Koichiro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Japan Atomic Energy Agency

    2011 - 2013

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    In order to estimate the damage on the inner surface of the structure, relationships between ultrasonic waveform and the amount of damage was clarified by using the contactless and remote controlled measuring technique. The optimal measurement conditions for detecting minute damage were found out. Because the ultrasonic wave propagating in the structure which includes the liquid was influenced the liquid, the influence was taken into account in the ultrasonic measurement. In consideration of the above result, the measuring system based on the laser Doppler vibrometer was developed and the vibration due to proton beams could be measured with sufficient accuracy to monitor the mercury target vessel. This measuring system can be applied as the monitoring system for the apparatus used under the extreme environment.

  12. 閉じたき裂評価のための非線形超音波映像法の開発 Competitive

    System: Grant-in-Aid for Scientific Research

    2009/04 - 2012/03

  13. 多種類の危険・有害ガスに対する携帯型高感度ガスセンサシステム Competitive

    System: JST Basic Research Programs (Core Research for Evolutional Science and Technology :CREST)

    2006/10 - 2011/03

  14. High resolution imaging of stress corrosion cracking by a confocal subharmonic ultrasonic phased array

    YAMANAKA Kazushi, OHARA Yoshikazu, TSUJI Toshihiro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    2009 - 2011

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    To ensure the safety and reliability of structures such as nuclear power plants, it is necessary to detect closed crack by nonlinear ultrasound. Though the novel imaging method, subharmonic phased array for crack evaluation (SPACE)is a practical solution, the lateral resolution was not high enough. In this research, we developed confocal SPACE with a single array transducer which can transmit a large amplitude focused wave and detect scattered wave using a single array sensor. We then succeeded to image an SCC in a heat affected zone (HAZ)of type 304 stainless steel specimen, formed in high temperature pressurized water, and succeeded in visualizing the closed crack tip in subharmonic image with high selectivity, irrespective of strong linear scattering at grain boundary. We also succeeded in 2D simulation of these waves. This result will significantly contribute to improve the safety and reliability of nuclear power plants.

  15. Development of nonlinear ultrasonic imaging method with low frequency vibration for closed cracks in large structures

    OHARA Yoshikazu

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (A)

    Category: Grant-in-Aid for Young Scientists (A)

    Institution: Tohoku University

    2009 - 2011

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    The aging damage has been accumulating in the large structures built during high economic growth period. To maintain safety and reliability of society, the means of evaluating them is necessary. The objective of this study is to develop the nonlinear ultrasonic imaging method with low-frequency vibration and phased array using pulse waves in order to visualize closed cracks in large structures with high resolution. In this study, we performed [1] development of the apparatus, [2] formation of closed-crack specimen, and [3] its verification test. As a result, we succeeded in imaging closed crack, formed in aluminum-alloy specimen, with high spatial resolution. Furthermore, we found that the selectivity for closed cracks in ultrasonic images was enhanced by 24 times. In addition, although the crack depth was underestimated by approximately 10 mm, we succeeded in measuring the crack depth with an accuracy of less than 1 mm using the developed method.

  16. 非線形超音波フェーズドアレイによる閉口き裂の評価法に関する研究 Competitive

    System: Funded Research

    2005/09 - 2008/02

  17. サブハーモニック超音波による新たな定量的き裂評価の統括的アプローチに関する研究 Competitive

    System: Special Postdoctoral Researchers Program

    2005/04 - 2007/03

  18. サブハーモニック超音波による新たな定量的き裂評価の統括的アプローチに関する研究

    小原 良和

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業 特別研究員奨励費

    Category: 特別研究員奨励費

    Institution: 東北大学

    2005 - 2006

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    本研究は、き裂非破壊評面の高信頼化における障壁である閉じたき裂検出の問題解決のための技術基盤の開発と学術基盤の確立を目的とするものである。高度経済成長期に集中的に建造された発電プラント、石油・化学プラント、橋梁、トンネルおよび高速道路などには、供用期間の増大とともに損傷・劣化が蓄積されている。循環型経済社会構築のために安全な長寿命化を実現するには、き裂を検出するのみでは不十分であり、その定量評価が不可欠である。き裂評価において従来、超音波が多く使われてきているが、閉じたき裂の見逃しという問題が未解決のまま残されていた。このなかで、非線形超音波法は、閉じたき裂でも大振幅超音波の応力でわずかに開口させて、入射超音波の整数倍の周波数をもつ高調波によりき裂を計測するため、閉じたき裂も検出できると期待されている。しかし、高調波はその発生度合いが小さい上、その発生源が閉じたき裂以外(探触子、探触子と試料の間のカップラント、電気回路など)にも存在する。一方、入射超音波の整数分の1の周波数のサブハーモニック波は、閉じたき裂のみが発生源であるため、従来の検査手法を大きく上回るパフォーマンスが期待されている。しかしながら、サブハーモニック波はまだ現象の解明が進んでいない。本研究では、超音波AFMの解析モデルをき裂面に導入することにより、理論モデルを構築し、この解析結果と実験結果を比較検討することで、サブハーモニック発生機構がき裂面の共振現象によることを解明した。閉じたき裂の画像化が可能な測定システムに発展させることを目的として、昨年度に構築した画像化アルゴリズムで画像化を行う際、適切なディジタルフィルタを設計・適用することで、線形(入力超音波の周波数)成分およびサブハーモニック成分を各々抽出し、解析を行った。その結果、線形像では過小評価してしまう閉じたき裂を、サブハーモニック像でのみ高精度に画像化できることを実証した。

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Social Activities 1

  1. 東北大学 イノベーションフェア

    2007/10/05 -

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    安全と安心のための先進超音波計測

Media Coverage 13

  1. Detecting cracks by understanding ultrasonic 3D scattering phenomena ― Scientific optimization of non-destructive testing techniques

    JST　Science Japan

    2022/09/27

    Type: Internet

  2. 超音波の3次元散乱現象を捉えてき裂を発見 ～非破壊評価技術を科学的に最適化～

    JST　JSTnews

    2022/08

    Type: Promotional material

  3. 東北大など、複雑な3D超音波散乱現象を解明するレーザスキャン技術の開発に成功

    日本経済新聞

    2022/05/25

    Type: Newspaper, magazine

  4. レーザービームのように真っ直ぐ伝わる音を操る！？超音波が支えるエコで安全な社会

    東北放送TBC　エンボヤージュ（en ∞ Voyage）

    2021/12/16

    Type: TV or radio program

  5. 東北大、冷却スプレーで亀裂を高感度計測

    航空新聞社　航空新聞社

    2021/11/04

    Type: Newspaper, magazine

  6. 閉じた亀裂を冷やして可視化 東北大、発電機など部材診断に提案

    日刊工業新聞　日刊工業新聞

    2021/11/02

    Type: Newspaper, magazine

  7. 東北大、材料内部の欠陥３Ｄ映像化 超音波センサー利用

    日刊工業新聞

    2020/09/25

    Type: Newspaper, magazine

  8. 東北大、構造物や工業製品の内部欠陥を3次元で可視化できる高分解能超音波映像法を開発

    日本経済新聞

    2020/09/23

    Type: Newspaper, magazine

  9. 若手研究者9人を表彰 トーキン科学財団

    河北新報

    2009/03/18

    Type: Newspaper, magazine

  10. 研究奨励賞5人に贈呈 青葉工学振興会

    2009/01/29

    Type: Newspaper, magazine

  11. 見えない亀裂 正確測定 -東北大のチーム 超音波装置開発-

    読売新聞

    2007/07/29

    Type: Newspaper, magazine

  12. 特殊周波数で高精度化 -東北大が超音波探傷装置-

    日刊工業新聞

    2007/07/09

    Type: Newspaper, magazine

  13. 超音波測定装置を開発 -東北大グループ実測との誤差縮小-

    河北新報

    2007/07/07

    Type: Newspaper, magazine

Show all Show first 5

Other 22

  1. レーザー超音波による、金属積層造形物の非破壊欠陥検出システム構築

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    本研究の目的は、レーザー超音波法を用い、インプロセスで金属積層造形物中の欠陥を検出するシステムの原理検証である。 積層造形装置は、任意形状を無の状態から作り出すので、超音波探傷のために事前に超音波の発振源と検出点を決められない。造形中に常に露出しているのは、粉末が溶融・凝固した積層造形面（造形の最上面）のみであるため、非接触で超音波発振と検出を行うのは、この面に限られる。造形面上の超音波の発振源をr(x,y)、計測点をr0 (x0,y0 )、計測された振動関数をφ(t,r,r0 )とすると、欠陥の面内分布を求めるためには、多くのrとr0においてφ(t,r,r0 )を計測する必要がある。しかし、干渉計による計測において計測点を自由に選択することは困難である。そこで、本提案者らの１人は、検出点は固定し、励起レーザーを走査することによって発振源を移動して得られるφ(r0) (t,r)を、波動の相反性を利用して解析することによって、材料の欠陥分布を映像化する技術を開発し、コンクリートに適用した。本提案では、これを積層造形物のインプロセス評価に適用する技術を開発する。

  2. 原子力規制委員会 原子力規制庁 高経年化技術評価高度化事業

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    高経年化が進行しつつあるプラントの寿命予測精度を向上させ、その科学的合理性を担保するため、劣化メカニズムに着目し、実験的手法及び解析的手法により劣化現象の解明等を行い、発生・進展の予測評価技術の高度化のための技術的基盤の整備を図る。また、得られた成果については、過去の研究成果、並びに本事業で実施してきた成果を踏まえ、安全規制基準、関連技術規格等への反映や実機適用に向けた方策の検討を行う。

  3. 天然ガスパイプライン検査のための超音波多重反射法の開発

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    シェールガスで注目を集める天然ガスのパイプラインなどでは、腐食による減肉が問題となっている。特に、配管と架台の接触部は探触子が直接アクセスできないため、検査不可能であった。本研究では、可変くさびと曲率を考慮した伝搬距離計算を用いる超音波多重反射法を提案し、その有効性を実証する。

  4. 電縫溶接部の閉口亀裂探傷に関する研究

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    従来技術と比べて検出性能の高いサブハーモニック超音波を送受信可能で、対象材形状の応じてフレキシブルに形状を変形できるプローブを試作し、性能評価を行う。

  5. 原子力発電所および使用済み燃料貯蔵キャスクの応力腐食割れの評価

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    原子力発電所および使用済み燃料貯蔵キャスクの応力腐食割れの評価

  6. 経済産業省 高経年化技術評価高度化事業

    More details Close

    高経年化が進行しつつあるプラントの寿命予測精度を向上させ、その科学的合理性を担保するため、劣化メカニズムに着目し、実験的手法及び解析的手法により劣化現象の解明等を行い、発生・進展の予測評価技術の高度化のための技術的基盤の整備を図る。また、得られた成果については、過去の研究成果、並びに本事業で実施してきた成果を踏まえ、安全規制基準、関連技術規格等への反映や実機適用に向けた方策の検討を行う。

  7. 電縫溶接部の閉口亀裂探傷に関する研究

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    従来技術と比べて検出性能の高いサブハーモニック超音波を送受信可能で、対象材形状の応じてフレキシブルに形状を変形できるプローブを試作し、性能評価を行う。

  8. 経済産業省 高経年化技術評価高度化事業

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    高経年化が進行しつつあるプラントの寿命予測精度を向上させ、その科学的合理性を担保するため、劣化メカニズムに着目し、実験的手法及び解析的手法により劣化現象の解明等を行い、発生・進展の予測評価技術の高度化のための技術的基盤の整備を図る。また、得られた成果については、過去の研究成果、並びに本事業で実施してきた成果を踏まえ、安全規制基準、関連技術規格等への反映や実機適用に向けた方策の検討を行う。

  9. 電縫溶接部の閉口亀裂探傷に関する研究

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    従来技術と比べて検出性能の高いサブハーモニック超音波を送受信可能で、対象材形状の応じてフレキシブルに形状を変形できるプローブを試作し、性能評価を行う。

  10. フレキシブルアレイを用いた曲面部材の閉じたき裂映像装置の創出

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    本研究では、曲面部材の閉じたき裂深さを高精度に計測できる曲面適応型SPACEの基盤技術確立を目的とする。 まず、曲面の検査に適したフレキシブルアレイ探触子の設計を行う。次に、映像化アルゴリズムの構築を行う。ここでは、SPACEの開発で蓄積してきた超音波フェーズドアレイの技術基盤を集約して、曲面形状を考慮した映像化アルゴリズムを構築する。そして、小径パイプなどの曲面部材内面に模擬欠陥を導入した実証用試験片を作製する。一方で、閉じたき裂の非線形超音波計測では、き裂面を開閉振動させる大振幅超音波の入射が必要なため、レーザー干渉計で変位計測を行い出力特性を評価する。最後に、本手法と従来の平面型探触子とを、感度・分解能・測定再現性の観点で比較し、本方法の有効性を実証する。

  11. 非線形フェーズドアレイ超音波探傷技術に関する研究

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    SCC探傷結果に対して、種々の探傷条件（例えば荷重、屈折角および周波数など）の影響を把握する。

  12. 東北・北海道クラスター 応力腐食割れ、状態監視保全

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    高経年化が進行しつつあるプラントの寿命予測精度を向上させ、その科学的合理性を担保するため、劣化メカニズムに着目し、実験的手法及び解析的手法により劣化現象の解明等を行い、発生・進展の予測評価技術の高度化のための技術的基盤の整備を図る。また、得られた成果については、過去の研究成果、並びに本事業で実施してきた成果を踏まえ、安全規制基準、関連技術規格等への反映や実機適用に向けた方策の検討を行う。

  13. 非線形超音波探傷技術に関する研究

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    非線形超音波法によるSCCの探傷結果について、定期的に論理的な実証を実施する。

  14. 高経年化対策強化基盤整備事業

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    高経年化が進行しつつあるプラントの寿命予測精度を向上させ、その科学的合理性を担保するため、劣化メカニズムに着目し、実験的手法及び解析的手法により劣化現象の解明等を行い、発生・進展の予測評価技術の高度化のための技術的基盤の整備を図る。また、得られた成果については、過去の研究成果、並びに本事業で実施してきた成果を踏まえ、安全規制基準、関連技術規格等への反映や実機適用に向けた方策の検討を行う。

  15. 閉じたき裂の広範囲な映像のためのサブハーモニック超音波フェーズドアレイ（SPACE）の高度化

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    本研究では、MEMS（Micro Electro Mechanical Systems）プロセスを用いて、偏向角を可変にできる大振幅超音波入射用LNアレイ（8素子）を作製し、広範囲の映像化を可能とするワイドレンジSPACEを提案する（図1）。さらに、その有効性を閉じたき裂試験体で実証することを目的とする。

  16. 非線形超音波技術に関する研究

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    SUS溶接部の応力腐食割れ（SCC）を対象として非線形超音波法の検出性・サイジング精度の把握および問題点を抽出する。

  17. 閉じたき裂評価のための先進超音波映像法SPACEの新展開

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    原子力発電の安全の重要性は一層高まっているが、配管などの原子炉構造物には、運転に伴って応力腐食割れ（SCC）や疲労き裂が発生する。これらのき裂は超音波探傷で検査され、損傷許容の維持規格に従って管理補修し運転が行われている。しかし、残留応力や界面酸化の影響でき裂が閉じている場合、超音波はき裂面を透過してしまうため、検査精度が大幅に低下する。これは、日本のみならず、原子力依存度の高いフランス、プラント建設ラッシュを迎えようとしている米国、中国においても重大な問題であり、閉じたき裂の高精度・高分解能計測法の開発は世界の原子力安全をリードするキーテクノロジーの一つである。本研究の目的は、き裂非破壊評価の高信頼化における障壁である閉じたき裂の高精度・高分解能映像法を開発することである。

  18. 閉じたき裂評価のための映像法SPACEの高分解能化

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    本研究では、複雑形状をもつ閉じたき裂を映像化するため、高耐圧圧電素子アレイを用いる高分解能SPACEを開発することを目的とする。

  19. 非線形超音波におけるレーザ計測技術の開発

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    レーザ超音波法等による非線形超音波計測技術の実用化技術の開発

  20. 非線形超音波法を利用した難検査欠陥検出技術に関する研究

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    非線形超音波システムを最適化し、従来の探傷手法による結果と比較・検討を行いその有効性について確認する。

  21. 多種類の危険・有害ガスに対する携帯型高感度ガスセンサシステム

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    生活空間、生産現場、交通機関などでは、多くの種類の危険・有害ガスがあるため、これを 数ppbの感度で迅速に測定して警報を発信するセンシング技術が求められています。これまで、これに応える技術として可搬型のガスクロマトグラフ（GC）が開発されてきましたが、ポケットに収納でき、個人が日常生活で使用できる携帯型のGCはまだ実現していません。本研究では、弾性表面波(SAW)センサを100倍高感度化したボールSAWセンサをGCの検出器として用い、GCのカラムが果たしてきたガスの選択性をセンサが分担する新しい分子計測法を開発して、MEMSで作製する小型のカラムやガス捕集器の機能を実効的に向上することで、ポケットに収納でき個人が日常生活で使用できる携帯型のGCを実現するとともに、計測データをセンサネットワークに発信する技術を開発します。

  22. 非線形超音波フェーズドアレイによる閉口き裂の評価法に関する研究

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    模擬閉口き裂試験体の製作、非線形超音波フェーズドアレイ装置による模擬試験体の計測及び評価、測定データの検証

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