LS-DYNA now offers a modified version of *MAT_CRUSHABLE_FOAM in the form of *MAT_MODIFIED_CRUSHABLE_FOAM . In the new material model, the strain rate effects can be included in the foam a *DEFINE_TABLE . To reduce or eliminate the noise in the evaulation of the new yield stress as a function of strain and strain-rate, LS-DYNA offers a modified strain-rate calculation and also a max variation of strain at every cyle. This is depicted in the following image.
When using this model, the effective plastic strain is replaced with the volumetric strain variable in D3PLOT for easy fringe plotting.