2004 Fiscal Year Final Research Report Summary
Fundamental Studies on the Limiting Velocity of Fast Dynamic Fracture in Solids
| Project/Area Number |
14205019
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Kobe University (2004)
神戸商船大学 (2002-2003) |
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Principal Investigator |
NISHIOKA Toshihisa Kobe University, Faculty of Maritime Sciences, Professor, 海事科学部, 教授 (60018067)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIMOTO Takehiro Kobe University, Faculty of Maritime Sciences, Associate Professor, 海事科学部, 助教授 (60314514)
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| Project Period (FY) |
2002 – 2004
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| Keywords | Moving Finite Element Method based on Delaunay Automatic Triangulation (MFEMBOAT) / crack tip total energy flow flux critical criterion / Coherent Gradient Sensing (CGS) Method / Ultrahigh-speed Video camera / Transonic Interface Fracture / Mach Shock wave / High Energy Fracture Testing Machine / マッハ衝撃波線 |
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| Research Abstract |
In experimental aspect, using the presently developed spring constraint loading machine, dynamic fracture tests in homogeneous materials were carried out. As the results, a limiting fast fracture that exceeds 75% of the shear wave velocity c_s of the material was successfully recorded by the presently developed world most advanced ultrahigh-speed video camera system (maximum framing rate : one million frames per second, 10 ns pulse exposure time) this fracture velocity exceeds the limiting crack velocity predicted by the near-tip singular stress field theory. However, taking account of the higher order terms of the near-tip stress field It was theoretically proved that the ultrahigh-sped straight fracture of.75^c_s is possible.to occur Furthermore, relation ship between crack-tip total energy flow flux (ψ_<totai> total energy flux in to the propagating crack tip per unit time) and fracture surface roughness was clarified. It was found that the fracture surface roughness increases for increasing ψ_<total>. Fracture surface roughness may triggers dynamic crack branching fracture.
The governing condition of dynamic crack branching has been a long-term unsolved problem for humankind. In our previous experimental studies, we have proved the critical crack-tip total energy flow flux criterion (dynamic two crack branching occurs when the crack-tip total energy flow flux ψ_<total> total exceeds a critical material value)
In our laboratory, very versatile moving finite element method based on Delaunay automatic triangulation (MFEMBOAT) has been developed. Using MFEMBOAT, dynamic multiple crack branching phenomena was firstly succeeded. The simulation results proved the critical crack-tip total energy flow flux criterion is also valid for the dynamic multiple crack branching.
Keywords : (1) 2),(3)Coherent Gradient Sensing(CGS)Method, (4)Ultrahigh-speed Video camera, (5)Transonic I Interface Fracture, (6)Mach Shock wave, (7)1High Energy Impact Fracture Testing Machine
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[Journal Article] The Observation of the Near-tip Field of Transonically Propagating Interfacial Crack2004
Author(s)
Nishioka, T., Endo, F, Fujimoto, T.
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Journal Title
The 2004 Society for Experimental Mechanics Annual Conference, June 7-10, 2004, osta Mesa, California, USA, The Proceedings of the 2004 Society for Experimental Mechanics, Session 95 Paper-No.169
Pages: 1-6
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Numerical Simulation of Impact Transonic Interfacial Fracture with the Crack Coalescence2004
Author(s)
Nishioka, T., Tsuda, T., Fujimto, T.
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Journal Title
1^<st> International Symposium on Explosion, Shock Wave and Hypervelocity Phenomena, Kumamoto University, Kumamoto, March 15-17, 2004 Vols.465-466
Pages: 61-66
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Prediction mode numerical simulation for non-straight propagating crack in elasto-plastic material2004
Author(s)
Nishioka, T., Oka, S., Fujimoto, T.
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Journal Title
International Conference on Computational Engineering and Science, Funchal, Portugal, July 26-29, The Proceedings of ICCES 2004, Chapter 19 No.563
Pages: 1881-1886
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Two-dimensional and Three-dimensional Moving Finite Element Analysis for High-speed Crack Propagation in Brittle Materials2004
Author(s)
Nishioka, T., Yamaguchi, K., Furuta, H., Fujimoto, T.
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Journal Title
International Conference on Computational Engineering and Science, Funchal, Portugal, July 26-29, The Proceedings of ICCES 2004, Chapter 19 No.562
Pages: 1893-1898
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Numerical Investigation of the Multiple Dynamic Crack Branching Phenomena2004
Author(s)
Nishioka, T., Tchouikov, S., Fujimoto, T.
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Journal Title
International Conference on Computational Engineering and Science, Funchal, Portugal, July 26-29, The Proceedings of ICCES 2004, Chapter 19 No.559
Pages: 1887-1892
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] T* Integral Analysis of Shell Structures with Through-Wall Cracks for Nonlinear Deformation Problems2004
Author(s)
Nishioka, T., Miyanishi, T., Fujimoto, T.
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Journal Title
International Conference on Computational Engineering and Sciences, Funchal, Portugal, July 26-29, The Proceedings of ICCES 2004, Chapter 19 No.561
Pages: 1875-1880
Description
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[Journal Article] Numerical Simulation of Impact Transonic Interfacial Fracture2003
Author(s)
Nishioka, T., Tsuda, T., Fujimoto, T.
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Journal Title
The 5th Inernational Conference on Fracture and Strength of Solids, Tohoku University, Sendai, Japan, October 20-22, Advances in Fracture and Failure Prevention (Trans Tech Publications Ltd.)
Pages: 301-306
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Moving Finite Element Method for Fracture Path Prediction in Materials Containing Inclusions and Voids2003
Author(s)
Nishioka, T., Kishimoto, K., Fujimoto, T.
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Journal Title
International Conference on Computational Engineering and Science, Corfu, Greece, July 25-29, The Proceedings of ICCES 2003, Chapter 2
Pages: 1-6
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] The Numerical Analysis of Crack Propagation Phenomenon Accompanied by the Acceleration and Deceleration using the Moving Finite Element Method based on Delaunay Automatic Triangulation2003
Author(s)
Nishioka, T., Furuta, H., Fujimoto, T.
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Journal Title
International Conference on Computational Engineering and Science, Corfu, Greece, July 25-29, The Proceedings of ICCES 2003, Chapter 2
Pages: 1-6
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Development of Numerical Simulation Technique on Kinking Fracture from Interfacial Cracks2003
Author(s)
Nishioka, T., Nukasaka, T., Fujimoto, T.
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Journal Title
International Conference on Computational Engineering and Science, Corfu, Greece, July 25-29, The Proceedings of ICCES 2003, Chapter 2
Pages: 1-6
Description
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[Journal Article] Study for High-Speed Crack Propagation Phenomena under Static Multi Loading System2003
Author(s)
Nishioka, T., Yamaguchi, K., Sakaguchi, H., Furuta, H., Sakakura K., Fujimoto, T.
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Journal Title
Japan Society of Experimental Mechanics Workshop 2003, Gero, Gifu, Japan, November 27-28
Pages: 22-27
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Measurements for Crack Propagation under Mixed Mode Loading in Ductile Materials2003
Author(s)
Fujimoto, T, Nao, H., Oka, S., Nishioka, T., Sakakura K.
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Journal Title
Japan Society of Experimental Mechanics Workshop 2003 Gero, Gifu, Japan
Pages: 33-36
Description
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[Journal Article] 衝撃破壊力学2002
Author(s)
西岡俊久
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Journal Title
材料,連載講座「材料の衝撃特性とその評価方法」 Vol.51, No.12
Pages: 1436-1442
Description
「研究成果報告書概要(和文)」より
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[Journal Article] Crack Kinking Criterion for Bimaterial System2002
Author(s)
Yao, J.L, Nishioka, T., Fujimoto, T., Nozaki, T.
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Journal Title
New and Emerging Computational Methods : Applications to Fracture, Damage, and Reliability (Brust, F.W., Nishioka, T.et al., editors) (ASME Publication) PVP-Vol.438
Pages: 163-170
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Impact Fracture Mechanics2002
Author(s)
Nishioka, T.
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Journal Title
Journal of the Society of Materials Science Japan, Lectures on Impact-Load Behavior of Materials and Its Evaluation Techniques Vol.51 No.12
Pages: 1436-1442
Description
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