Adiabatic shearing of non-homogeneous thermoviscoplastic materials

In this work we present the role of material non-homogeneities, driven by position-dependent thermomechanical parameters on the emergence, evolution and localization of temperature and strain non-uniformities during the shearing of thermoviscoplastic materials of the rate type. We first present the solution of the quasistatic approximation and show the existence of two stages: the first is characterized by a possible “travelling” of non-uniformities, due to non-homogeneities, while in the second the non-uniformities localize and increase at regions with intense heterogeneities. Moreover, we show that, even under stability conditions, the non-uniformities increase at material regions with inhomogeneities, which affect both their spatial distribution and time evolution. The related strain non-uniformities in the form of shear banding, as well as the comparison with the non-uniformities caused by initial defects or temperature gradient, are presented. Finally, numerical results confirm the analytical findings.