| Project/Area Number |
07650127
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | SUZUKA NATIONAL COLLEGE OF TECHNOLOGY |
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Principal Investigator |
TSUJI Masatoshi SUZUKA NATIONAL COLLEGE OF TECHNOLOGY,Department of Mechanical Engineering, Professor, 機械工学科, 教授 (60043296)
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| Co-Investigator(Kenkyū-buntansha) |
TAMURA Youjiro SUZUKA NATIONAL COLLEGE OF TECHNOLOGY,Department of Physics, Associate Professor, 物理教室, 助教授 (20163701)
SAITO Masami SUZUKA NATIONAL COLLEGE OF TECHNOLOGY,Department of Electronic & Information Eng, 電子情報工学科, 教授 (30149934)
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| Project Period (FY) |
1995 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1997: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1996: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1995: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | METAL FRACTURE / STRUCTURE OF FRACTURE / SIMULATION / FRACTAL / シミュレーション / 金属破面 |
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| Research Abstract |
To quantify the structure of metal brittle-fracture surface, a concept of "Fractal character" had been used. The results of our experiments for an aluminum alloy 7075 and cast iron suggest that the geometrical structure of fracture surface is affected by the micro-scale unevenness of mechanical properties and the distribution of the internal residual stress. Accordingly, to understand the relation between the internal state of material and the geometry of fracture surface, we conduct computer simulation of crack propagation by means of Finite Element Method for an imaginary metal plate with a random distribution of internal distortion energy. This two-dimensional model plate is made of imaginary crystals of comparable grain sizes. The voids and the soft impurities this model is assumed to be the elements with the small modulus of elasticity. The derivatives and the hard impurities are assumed to be the elements with the large modulus of elasticity and arise the energy distribution in the neighborhood. A small defect (the source of fracture) is made near the middle of the model. This model is being in the initial condition of residual energy distribution and suffered by a uniform tension of magnitude 1 in the x-direction and y-direction as the boundary and load condition. Carrying out this simulation, the stresses and distortion energy within every elements in this model are calculated. We assume that the fracture occurs at the element of maximum stress or distortion energy and delete this element. Repeating in this process, the defect glow up to be a fracture from a viewpoint of macroscopic.
This results of simulation for the structure of fracture surface are as follows.
(1) The progress of fracture branch off with arbitrary direction.
(2) The structure of fracture surface is a complex shape.
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