| Project/Area Number |
07555346
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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 | 展開研究 |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Nagoya University |
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Principal Investigator |
MURAKAMI Sumio Nagoya University, Department of Mechanical Engineering, Professor, 工学部, 教授 (10023053)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Takayuki CRC Research Institute, Inc., Structural Engineering Department, Manager, 構造技術部, 部長
SUGITA Yuji Chubu Electric Power Company, Inc., Electric Power Research and Development Cent, 電力技術研究所, 主幹研究員
TOKUDA Masataka Mie University, Department of Mechanical Engineering, Professor, 工学部, 教授 (90023233)
LIU Yan Nagoya University, Department of Mechanical Engineering, Assistant Professor, 工学研究科, 助手 (10262859)
TANAKA Eiichi Nagoya University, Department of Mechanical Engineering, Professor, 工学研究科, 教授 (00111831)
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| Project Period (FY) |
1995 – 1997
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| Keywords | Simulation / Damage / Fracture / Structure / Crack Growth / Life-Time Prediction / Damage Mechanics / Finite Element Method |
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| Research Abstract |
The present project aims at the development of a systematic and unified computational technique for fracture and life-time prediction of structural elements by means of Continuum Damage Mechanics (CDM) and Finite Element Method (FEM). By simulating a crack by an aggregate of fractured finite elements, the whole process of damage, crack growth and final fracture can be analyzed. The major results of the present project are summarized as follows :
1. A simulation system of damage and fracture process was developed by incorporating damage evolution equation and inelastic constitutive equations into commercial Finite Element Program and by modeling a crack by an aggregate of fractured finite elements.
2. In order to establish a system of creep crack growth in structural components at elevated temperature, the causes of mesh-dependence of the numerical results are discussed. The effects of stress sensitivity of the damage evolution equation and those of the preceding damage field on the stress singularity at the crack-tip were elucidated.
3. A damage evolution equation for fatigue was formulated by the use of the experimental results of SA508 pressure vessel steel for nuclear reactors, and a fatigue damaged process of notched specimens was analyzed.
4. In order to establish a more systematic framework of damage evolution equations, an elastic-plastic-damage theory was developed on the basis of Gibbs thermodynamic potential.
5. By analyzing the effect of the preceding damage field on the stress singularity at a crack-tip, the condition for the crack-tip stress field to be non-singular was discussed. This analysis elucidated the mathematical structure of the mesh-dependence observed in the damage and fracture simulation method based on CDM and FEM.
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