Benchmarking iSALE and CTH Shock Physics Codes to In Situ High‐Velocity Impact Experiments Into Fe‐Ni Targets

Abstract

Abstract Cratering is a prominent evolutionary process on asteroids. Crater morphologies, regolith generation, bulk fracturing and projectile implantation are all examples of asteroidal surface evolution resulting from impact processes. The characterization of these processes on metal‐rich bodies has become a priority due to the upcoming NASA Psyche mission, poised to study the likely metal‐rich 225‐km main belt asteroid, (16) Psyche. Small‐scale impact experiments into metals (e.g., iron, aluminum, copper, steel) have shown that crater morphologies into these materials are different than rocky targets—exhibiting notable distinctive features such as raised, sharp rims, and deeper cavities. In this work, we determine strength constants for different metals used in prior impact experiments, namely manufactured Fe‐Ni materials and the Gibeon iron meteorite at 77 K. These parameters have been used as inputs for the Johnson and Cook (1983) strength model in a suite of numerical simulations reproducing impact experiments. Using the Johnson and Cook strength model and our laboratory‐derived material constants, we find that it is possible to closely match small‐scale experimental crater diameters and depths using iSALE and CTH shock physics codes.