| Project/Area Number |
62550520
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属材料(含表面処理・腐食防食)
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| Research Institution | Kyoto University |
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Principal Investigator |
SHOJIRO OCHIAI Faculty of Engineering, Kyoto University , Associate Professor., 工学部, 助教授 (30111925)
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| Co-Investigator(Kenkyū-buntansha) |
KOZO OSAMURA Faculty of Engineering, Kyoto University , Professor., 工学部, 教授 (50026209)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1988: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1987: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Composite Material / Hybrid Composite / Tensile Strength / Stress Concentration / Fracture Toughness / モンテカルロシミュレーション / 引張り強さ / 応力集中臨界アスペクト比モンテカルロシミュレーション / 金属マトリックス / 伸び |
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| Research Abstract |
In order to improve tensile strength and fracture toughness of fiber-reinforced metal matrix composites, hybridization was tried by embeddening second fibers in addition to the first main fibers. Two possible mechanisms to improve the mechanical properties by the hybridization were examined theoretically and experimentally; (i)debonding at interface between the second fibers and matrix, which reduces stress concentration and (ii)suppression of propagation of cracks at the second fibers with high failure strain. It was clarified that these mechanisms are very effective for the improvements. The problems (a)how to estimate the stress concentration in hybrid composites, (b)how to predict the tensile strength of hybrid composites and (c)the possibility to predict fracture toughness of hybrid composites were studied theoretically. The problem (a) was overcome by employing the shear-lag-analysis method and (b) by employing the Monte-Carlo simulation method. (c) was also tried by the Monte-Carlo simulation method, which could reproduce fracture process of fibers fairly well. However, at present, quantitative prediction by this method was not successful due to lack of details concerning interfacial bonding strength and frictional stress acting after debonding at interface.
In conclusion of the present work, the hybridization is one of the most effective methods to improve strength and toughness of composite materials. This was verified theoretically and experimentally.
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