Impact Crater Scaling Laws

Abstract

The effects of the impactor size and velocity, of the material properties of the impactor and impacted body, and of the gravitational field strength were examined. The dependence of the coupling parameter on the Gruniesen parameter and the us/up slope values that characterize a Tillotson material model were tested. Whether a code calculation can recover the scaling exponents that can be derived theoretically for an idealized perfectly-porous material that crushes at zero strength and subsequently is incompressible was investigated. A model that was close to the idealized case was generated in a form suitable for code calculations and utilized for a series of one dimensional calculations. The code calculation demonstrated the theoretical coupling parameter. Calculations of impacts using a physically real porous material model seem to indicate a coupling parameter of the same form applicable to a nonporous material, distinctly different from that expected from other theoretical and experimental results for porous materials. The one dimensional calculations are being extended to two dimensional impacts.