Laboratory simulation of planetesimal collision
Low-velocity impact experiment on rocks was performed to reveal a nature of collision process of planetesimals. Projectiles of mild steel (S15CK) and rocks (tuff and basalt) with velocities of 17 to 270 m/s were impacted against four kinds of rocks (tuff, basalt, granite, and dunite) with various shapes and sizes. Imparted energy divided by target mass E/sub i/ ranges 10/sup 6/ to 10/sup 8/ erg/g. The phenomena associated with the impact of mild steel against spherical targets were classified into five categories. The categories vary with increase in impact velocity as follows: (1) rebound of projectile with no contact damage on target, (2) rebound of projectile with fragmentary chips, and creations of a contact damage (crater.) and radiating fissures on target, (3) rebound of projectile with longitudinal splitting of target, (4) destruction of target with producing shatter conelike fragments, and (5) complete destruction of target. We cannot see any difference in the above categories between various kinds of rocks. The shape of the target also does not influence the categories significantly. The size distribution of the fragments produced by the complete destruction was well expressed by an inverse power law relation. n(l) dlproportionall/sup -alpha-1/ dl, where n(l) is the incremental number of the fragments within a linear increment dl. l is the size, and ..cap alpha.. is constant; ..cap alpha.. seems to increase with increase in E/sub i/. An empirical relationship between ..cap alpha.. and E/sub i/ was approximately given by ..cap alpha..proportionallog E/sub i/. Empirical formulae for the maximum fragment mass normalized by the original target mass (M/sub l/ /M/sub t/) and E/sub i/ were also presented for each rock type.
- Research Organization:
- Geophysical Institute, Faculty of Science, University of Tokyo, Bunkyo-ku Tokyo 113, Japan
- OSTI ID:
- 6149992
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 87:B13
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
PLANET-SYSTEM ACCRETION
GRAIN GROWTH
SIMULATION
BACKSCATTERING
COLLISIONS
FRACTURES
GRAIN SIZE
IMPACT STRENGTH
CRYSTAL STRUCTURE
FAILURES
MECHANICAL PROPERTIES
MICROSTRUCTURE
SCATTERING
SIZE
640107* - Astrophysics & Cosmology- Planetary Phenomena