Shock viscosity and the prediction of shock wave rise times

Abstract

The present study is focused on viscouslike behavior of solids during large-amplitude compressive stress-wave propagation. Maximum strain rate in the plastic wave has been determined for 30 steady- or near steady-wave profiles obtained with velocity interferometry methods. The materials include six metals, aluminum, beryllium, bismuth, copper, iron, and uranium, and two insulating solids, magnesium oxide and fused silica. A plot of Hugoniot stress versus maximum strain rate for each material is adequately described by η̇=aσmh. The exponent m is approximately 4 for all materials while the coefficient a is material dependent. A model is developed which incorporates the observed trends of the shock viscosity data in a three-dimensional framework. Finite-difference calculations using the model reproduce the experimental wave profile data.