On collisional disruption - Experimental results and scaling laws

Abstract We present results from an experimental program designed to measure impact strengths, fragment sizes, and fragment velocities resulting from the collisional shattering of cement mortar targets having crushing strengths which vary by an order of magnitude. Both homogeneous and nonhomogeneous targets, together with a variety of projectile types, are used in 116 shots covering a velocity range from 50 to 5700 m/sec. The impact strengths of strong and weak homogeneous mortar targets are found to be nearly identical, contrary to what would be expected from their static strengths. However, combining our data with other published results shows that the dynamic impact strength is correlated with quasi-static material strengths for most materials ranging from basalt to ice. Two materials that do not follow this trend are the weak mortar used in this program and the clay targets used by A. Fujiwara and N. Asada (1983, Icarus 56, 590–602). A simple scaling algorithm based on impact energy, material properties, and collisional strain rate is shown to predict values which are consistent with experimental results for the size of the largest collisional fragment. Data on fragment velocities are given for 30 of our collisional experiments, and we find a shallower exponent for the mass-velocity distribution resulting from catastrophic collisions as compared with cratering impacts into sand.

[1]  T. Ahrens,et al.  Impact-induced energy partitioning, melting, and vaporization on terrestrial planets , 1977 .

[2]  Alan W. Harris,et al.  Collisional evolution of asteroids - Populations, rotations, and velocities , 1979 .

[3]  T. Ahrens,et al.  Fragmentation of ice by low velocity impact , 1982 .

[4]  J. Lipkin,et al.  Criteria for impulsive rock fracture , 1980 .

[5]  A. Fujiwara,et al.  Impact fracture patterns on phobos ellipsoids , 1983 .

[6]  D. Davis,et al.  Asteroid Collisional Evolution: Evidence for a Much Larger Early Population , 1975, Science.

[7]  M. E. Kipp,et al.  Continuum modelling of explosive fracture in oil shale , 1980 .

[8]  William K. Hartmann,et al.  Planetesimals to planets: Numerical simulation of collisional evolution , 1978 .

[9]  Y. Takagi,et al.  Impact experiments on ice , 1983 .

[10]  T. Matsui,et al.  Laboratory simulation of planetesimal collision , 1982 .

[11]  T. Ahrens,et al.  The dynamic tensile strength of ice and ice‐silicate mixtures , 1983 .

[12]  P. Farinella,et al.  The asteroids as outcomes of catastrophic collisions , 1982 .

[13]  Donald E. Gault,et al.  The destruction of tektites by micrometeoroid impact , 1969 .

[14]  P. N. Smith,et al.  Asteroidal catastrophic collisions simulated by hypervelocity impact experiments , 1986 .

[15]  A. Fujiwara.  Complete fragmentation of the parent bodies of Themis, Eos, and Koronis families , 1982 .

[16]  H. J. Moore,et al.  Spray Ejected from the Lunar Surface by Meteoroid Impact , 1963 .

[17]  Akira Fujiwara,et al.  Destruction of basaltic bodies by high-velocity impact , 1977 .

[18]  A. A. Griffith.  The Phenomena of Rupture and Flow in Solids , 1921 .

[19]  Andrew Nagy,et al.  The dynamic strength and fracture properties of dresser basalt , 1974 .

[20]  A. Fujiwara,et al.  Rotation of fragments in catastrophic impact , 1981 .

[21]  Impact experiments on H_2O ice. II: Collisional disruption , 1985 .

[22]  D. Davis,et al.  Experiments and scaling laws for catastrophic collisions , 1989 .

[23]  Akira Fujiwara,et al.  Experimental study on the velocity of fragments in collisional breakup , 1980 .

[24]  Y. Takagi,et al.  Impact fragmentation experiments of basalts and pyrophyllites , 1984 .

[25]  T. Matsui,et al.  Destruction of rocks by low velocity impact and its implications for accretion and fragmentation processes of planetesimals , 1984 .

[26]  D. Davis,et al.  Collisional history of asteroids: Evidence from Vesta and the Hirayama families , 1985 .

[27]  K. A. Holsapple,et al.  Scaling laws for the catastrophic collisions of asteroids , 1986 .

[28]  L. E. Malvern,et al.  Dynamic Compressive Strength of Cementitious Materials , 1985 .

[29]  W. Hartmann.  Terrestrial, lunar, and interplanetary rock fragmentation , 1969 .

[30]  G. Polkowski,et al.  Experimental hypervelocity impact into quartz sand: Distribution and shock metamorphism of ejecta , 1975 .