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=aσ m h . 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.