The initiation and growth of, and the interaction among, adiabatic shear bands in simple and dipolar materials

Abstract

Abstract The problem of simple shearing of a block simple (nonpolar) and dipolar thermoviscoplastic materials is studied with the objectives of exploring the initiation and growth of, and the interaction among, adiabatic shear bands. A shear band is assumed to have formed if the addition of a perturbation to the homogeneous fields just before the peak stress is reached results in a localization of the shear strain. The effect of adding perturbations of different sizes and of the same size but at different locations in the slab is investigated. It is shown that in simple materials, two shear bands coalesce if the distance between them is small but grow independently, although at a slower rate, if the distance between them is large. However, for dipolar materials, the two bands coalesce even when the distance between them at the time of their initiation is 20 times the material characteristic length.