Single two-zone elastic-plastic shock waves in solids

Abstract

A new regime of shock wave propagation, characterized by a single two-zone elastic-plastic shock wave structure, has been found in moving window molecular dynamics simulations. This single two-zone wave consists of a leading low-pressure elastic zone followed by a high-pressure plastic zone, both moving with the same speed and having a fixed net thickness that may extend to many microns. The elastic zone is made up of material in a metastable state exhibiting pressures that can substantially exceed the Hugoniot elastic limit. The two-zone elastic-plastic wave is a quite general phenomenon observed in simulations of a broad class of crystalline materials. It is the existence of the two-zone, elastic-plastic regime that allows for a consistent explanation of the anomalously high elastic wave amplitudes observed in recent experiments. © 2012 American Institute of Physics.