| Project/Area Number |
03640364
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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 |
固体地球物理学
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| Research Institution | TOHO GAKUEN JUNIOR COLLEGE |
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Principal Investigator |
TAKAGI Yasuhiko TOho Gakuen Junior College, Associate Professor, 商経科, 講師 (10192147)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Manabu Nagoya University, Department of Earth & Planetary Sciences, Associate Professor, 理学部, 助教授 (80115550)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1992: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1991: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Impact experiment / Planetary formation process / Scaling law / Shock wave / Velocity distribution / スケ-リング則 |
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| Research Abstract |
Impact experiments of cubic pyrophyllites were performed in a velocity range of 400 to 900 m/sec. Motions of fragments were recorded by a high-speed movie camera. Three-dimensional velocities were determined from analyses of films. obtained results are :
1. Fragment velocity dependence on the fragment mass proposed by other research groups was not observed.
2. Average of fragment velocities of a single run is proportional to the nondimensional impact stress (NDIS) parameter. The NDIS parameter is the shock wave pressure at the rear surface of a target normalized by the target strength.
3. Fragment velocities in a single run are proportional to d to the power -4/5, where d is the distance from the shot point to the initial position of the fragment.
4. Fragment velocities of all the experiments are proportional P to the power 1/4, where P is the shock wave pressure at the initial position of the fragment.
These relations are not derived from the definition of NDIS straightforwardly. However, these results indicated that it is necessary to elucidate the peak pressure generated by an impact, the size and shape of high-pressure region, and the decay rate of the pressure for the definition of the scaling law of impact fragmentation phenomena. It is also shown that the NDIS is an appropriate parameter for the fragment velocities as well as size distributions.
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