Close-in blast loading of a steel disc; sensitivity to steel strength modeling

Abstract

The EPIC Lagrangian wavecode is used to simulate four experiments, in each of which a circular disc of rolled homogeneous armor (RHA) was loaded by the detonation of a nearby, bare, cylindrical charge of Octol. The disc's radius equals 76.2 mm, and its thickness is either 12.7 or 25.4 mm.The charge has a length-to-radius ratio of 4.32, and its radius is either 38.3 or 41.2 mm.Two strength models, Johnson-Cook and Zerilli-Armstrong, are applied to the RHA in the simulations. For each model, a published set of parameter values is found to produce results in reasonable agreement with experiment in terms of the disc's steady-state center-of-mass velocity and “swept-back volume,” a measure of the final plastic bending.