2 Methods
We simulated all 18 of the vertical (90 degrees, overhead) impacts from Marchi et al. (2020) (Table 1) into the Fe-Ni ingots and iron meteorite Gibeon targets using the iSALE-2D shock physics code and two (#2.06 and #2.11 from Table 1) using the CTH shock physics suite. iSALE is an extension of the SALE hydrocode (Amsden et al., 1980). To simulate hypervelocity impact processes in solid materials SALE was modified to include an elasto-plastic constitutive model, fragmentation models, various equations of state (EoS), and multiple materials (Melosh et al., 1992; Ivanov et al., 1997). More recent improvements include a modified strength model (Collins et al., 2004), a porosity compaction model (Wünnemann et al., 2006; Collins et al., 2011) and a dilatancy model (Collins, 2014). CTH is an Eulerian shock-physics code developed at Sandia National Laboratories (McGlaun et al., 1990) and has been used for a variety of high-velocity deformation problems (including planetary cratering). CTH has models for multi-phase, elastic, viscoplastic, porous, and energetic materials. Three-dimensional rectangular meshes, two-dimensional rectangular and cylindrical meshes, as well as one-dimensional rectilinear, cylindrical, and spherical meshes are available. CTH can utilize adaptive mesh refinement and uses second-order accurate numerical methods that reduce dispersion and dissipation to produce accurate and efficient results.