| Project/Area Number |
03452193
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
船舶構造・建造
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| Research Institution | University of Tokyo |
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Principal Investigator |
MACHIDA Susumu Univ.of Tokyo Fac.of Eng.Professor, 工学部, 教授 (70010692)
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| Co-Investigator(Kenkyū-buntansha) |
KANEDA Shigehiro Univ.of Tokyo Fac.of Eng.Assistant, 工学部, 助手 (90010892)
NIIMURA Yutaka Univ.of Tokyo Fac.of Eng.Assistant, 工学部, 助手 (40010889)
YOSHINARI Hitoshi Univ.of Tokyo Fac.of Eng.A.Professor, 工学部, 助教授 (20167737)
MATOBA Masaaki Univ.of Tokyo Fac.of Eng.A.Professor, 工学部, 助教授 (10229594)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥6,700,000 (Direct Cost: ¥6,700,000)
Fiscal Year 1992: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 1991: ¥3,900,000 (Direct Cost: ¥3,900,000)
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| Keywords | Brittle Crack / Arrest Toughness / Cleavage Fracture Stress / Local Fracture Criterion / Energy Release Rate / HRR Stres Field / Long Crack / 長大ぜい性き裂 / 伝播停止 / 塑性波拡大モデル / エネルギ-論 / 応力論 / 伝播シミュレ-ション |
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| Research Abstract |
Crack arrestability of the material has been measured by a crack arrest toughness K_<ca> based on fracture mechanics concept. Recent experimental studies involving dynamic fracture mechanics analysis show that there is a discrepancy between crack arrest property associated with relatively short arrested crack and that with very long crack. This discrepancy may come from the fact that these analyzes are essentially based on Griffith type energy criterion, which is nothing but a necessary condition. Thus, local stress criterion which might be a sufficient condition should be taken into account in order to clarify the crack arrest behavior.
In this study, a simple model for brittle crack propagation and arrest in structural steel is proposed. The hall's model is modified to account for plastic work done in the crack tip region, and HRR stress field is assumed to evaluate crack tip local stress. Based on the model proposed, brittle crack propagation and arrest behaviors simulating both conventional and wide plate experiments are analyzed. The results show that local stress criterion rather than energy criterion controls the crack run-arrest process in structual steel.
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