A numerical study of the dynamic inelasticity under compression-shear ramp wave loading

A new experimental technique has recently been developed at Sandia National Labs to measure the dynamic material strength at high pressures using ``magnetically applied pressure shear (MAPS)'' ramp waves. The objective of this study is to use numerical simulation to gain insight on the inelastic material response to such loading and develop a knowledge basis for further development and improvement of the technique. Two different materials were studied. One was FCC aluminum which was described by a simple viscoplastic model and the other was BCC tantalum described by a dislocation density based model developed in a previous work. The responses of these models to non-proportional compression-shear loading; effects of rate sensitivity, pressure dependence of strength, and wave interaction on shear wave propagation; and the correlation between in-situ inelastic behavior and measured experimental output were investigated and compared with the available experimental data.