A shear banding model for penetration calculations

A model for introducing the effects of adiabatic shear banding into a penetration calculation was installed into the EPIC wavecode. The model makes use of a strain-rate-dependent instability strain. Thereafter a modified constant-strain-rate, torsional von Mises stress-equivalent plastic strain curve is imposed on a finite element. The modification, motivated by the existence of superimposed pressure, is a pressure-dependent residual strength in an element associated with fully formed shear bands. The model also imposes an increase in spall pressure. An application to a set of problems involving steel plate perforation by a tungsten rod is considered.