| Project/Area Number |
06452150
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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 |
Materials/Mechanics of materials
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| Research Institution | Osaka University |
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Principal Investigator |
KITAGAWA Hiroshi Osaka University, department of Mechanical Engineering, Professor, 工学部, 教授 (30029095)
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| Co-Investigator(Kenkyū-buntansha) |
OGATA Shigeo Osaka University, department of Mechanical Engineering, Assistant, 工学部, 助手 (20273584)
NAKATANI Akihiro Osaka University, Department of Mechanical Engineering, Assistant Professor, 工学部, 講師 (50252606)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1995: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1994: ¥4,800,000 (Direct Cost: ¥4,800,000)
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| Keywords | Molecular Dynamics / Grain Boundary / Grain Boundary Diffusion / Amorphous Metal / Ab initio Estimation / Strain Migration / Meso-scale Structure / アモルファス / 金属材料 / 材料強度評価 |
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| Research Abstract |
Molecular dynamics simulations have been performed to investigate the mutual interactions (not causal relations) between the macroscopic phenomena and microscale events, which govern the strength properties of metal. The main results obtained and problems examined are :
(1) On the basis of the first-principle analysis, the effective medium theory is proved to give the accurate estimation for interatomic interaction even for locally inhomogeneous atomic structure and its non-equilibrium change.
(2) Concerning the mono-atomic amorphous structure obtained through simulation of melting-rapid cooling process, relations between the mechanical properties and change of the geometric structures in atomic scale under external loading are examined. It is proved that the basic frame structure formed by icosahedral Boronoi polyhedra which is the most stable atomic arrangement with the short-range order structure plays an important role for strength properties.
(3) Relations between the grain boundary (excess) energy and the ideal cleavage/shear strength and the diffusional properties near the aluminum grain boundary with the symmetric tilt/twist structure are studied. The fundamental features on the stress/electro migration in thin film or wire are discussed on from anisotropy of atomic diffusion.
(4) Continuum modeling approach to treat the meso-scale structure based on the crystal plasticity theory and homogenization method are investigated and method for formulation of the constitutive relation reflecting the information obtained from atomic scale simulation are discussed.
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