| Project/Area Number |
61420023
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
機械材料工学
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| Research Institution | SCIENCE UNIVERSITY OF TOKYO |
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Principal Investigator |
KAWATA Kozo PROFESSOR, FACULTY OF INDUSTRIAL SCIENCE AND TECHNOLOGY, 基礎工学部, 教授 (70013612)
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| Co-Investigator(Kenkyū-buntansha) |
MIYAMOTO Iwao LECTURER, FACULTY OF SCIENCE AND TECHNOLOGY, 理工学部, 講師 (10084477)
SAWA Yohiaki ASSOCIATE PROFESSOR, FACULTY OF SCIENCE AND TECHLOGY, 理工学部, 助教授 (60101309)
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| Project Period (FY) |
1986 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥21,000,000 (Direct Cost: ¥21,000,000)
Fiscal Year 1988: ¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1987: ¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 1986: ¥10,500,000 (Direct Cost: ¥10,500,000)
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| Keywords | High velocity solid mechanics / impact / high velocity brittleness / high velocity ductility / structural solids / 高速固体力学 / 高速変形 / 耐衝撃性 / 弾性棒法 / 高歪速応 / 固体力学物性 / 高速引張り |
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| Research Abstract |
1. The system for the characterization of materials in high velocity tension that can give the dynamic tensile stress-strain diagrams up to complete breaking, in the strain rate range up to lx10^4/s was established, basing upon the "one bar method" formulae proposed by Kawata et al. The effective time duration ranges up to 1160 microsecond, the longest record in the world.
2. The data on complete tensile stress-strain raletion in 10^3/s range and the phenomena of the velocity brittleness and high velocity ductility were clari-fied for various categories of solids: pure metals, alloys, composites, polymers, and ceramics.
3. Pure metals: (1) Generally speaking, obtained wide results support well crystal lattice systems effect on high velocity brittleness proposed by Kawata in 1978. (2) Pure iron show drastic high velocity brittlness. And this seems the fundamental behaviour of BCC metals. This property should be suppressed in practical structural materials. (3) The flow stress of OFHC copper shows clear upper deviation from log strain rate proportionality in 10^3/s range in tension, suggesting the transition of deformation mechanism to visous type from thermal activation type.
4. In the categories of alloys, composites, polymers and ceramics, also, many ramarkable results on high velocity brittleness and high velocity ductility were obtained. Some examples are: remarkable high velocity ductility of GFRP, incres-ing of absorbed energy of PC in 10^3/s range, high velocity ductility of Pyrex glas fiber, extreme high velocity brittleness of PET and Nylon 12 etc.
5. Details should be referred to the 39 papers published shown in Full Report.
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