Development of a model for simulating brittle crack propagation and arrest behavior and clarification of the long crack problem

2018 Fiscal Year Final Research Report

• Project/Area Number: 15H05561
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Naval and maritime engineering
• Research Institution: The University of Tokyo
• Principal Investigator: Shibanuma Kazuki 東京大学, 大学院工学系研究科(工学部), 准教授 (30611826)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 脆性破壊 / 亀裂伝播 / アレスト / 長大亀裂問題

Outline of Final Research Achievements

In this study, we obtained four achievements as follows. (1) We developed a fracture mechanics model for simulating brittle crack propagation and arrest behavior in a steel plate based on the local fracture stress criterion and the crack closure effect by side ligaments. (2) Validation of the proposed model was performed by comparing with several experiments of several large-scale fracture tests. (3) We estimated the material property necessary for the arrest design of the actual structures by systematic calculations using the proposed model. (4) The validity of the local fracture stress criterion was validated using experiments and finite element analysis.

Free Research Field

破壊力学

Academic Significance and Societal Importance of the Research Achievements

本研究で得られた成果は，40年以上未解決である長大亀裂問題を解明しただけでなく，構造基盤材料の「アレスト靱性」に本質的意味を与える挑戦的な試みであった．また，本研究の成果は，海上輸送構造物の安全性確保に直接的に貢献する基盤技術でもある．したがって本研究の成果は学術的・社会的価値を両立した工学研究であるといえる．