Plastic flow in close-packed crystals via nonequilibrium molecular dynamics

Abstract

The measurement of plastic-wave profiles in strong shock waves suggests a power-law dependence of the solid-phase shear stress on strain rate. The strain rates in these experiments vary from about 10 kHz to 0.1 GHz. We have carried out molecular-dynamics simulations of steady-state plastic flow in two- and three-dimensional close-packed crystals, using recently developed "nonequilibrium" equations of motion to maintain a constant strain rate and temperature. These calculations appear to be consistent with current experimental data and suggest that the flow of close-packed metals is described by a single physical mechanism over a range of strain rates from 10 kHz to 1 THz.