Plasticity at High Pressures and Strain Rates Using Oblique-Impact Isentropic-Compression Experiments

Abstract

Part of LLNL’s national security mission is reliant on accurate simulations of high strain-rate plastic flow (nonreversible deformation) under conditions of high hydrostatic pressures. In an effort to help advance the predictive capability of LLNL’s multiscale modeling program a new experimental technique has been developed to provide strength properties under conditions of high strain rate (104 -106 s-1) and high hydrostatic pressure (1- 100 GPa). The oblique-impact experiments allow for the shearing response of the material to be independently measured while the material is under pressure. The strength of the material is then inferred by conducting 2-D hydrodynamic simulations to match to the experimentally measured velocity profiles. Utilizing this technique, Cu and V experiments have been conducted that establish the utility of this technique to measure strength under dynamic conditions.