A Large Deformation Plasticity Model With Rate Sensitivity and Thermal Softening

Abstract

In this paper, a previously published small deformation constitutive model with rate sensitive plasticity and thermal softening is extended to large deformation. The extended model appears suitable for describing a deleterious thermoplastic process manifested by adiabatic shear banding in materials such as titanium under severe dynamic loads. The nature of the instability admitted by the model is described. Also, calculations are reported on the rapid extension of a titanium strip. For applied stresses several times the yield stress, a deleterious temperature is attained in times of the order of 10−2 s.