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.