Effect of multiple initial imperfections on the initiation and growth of adiabatic shear bands in nonpolar and dipolar materials

摘要: Abstract Simple shearing deformations of a viscoplastic block made nonpolar and dipolar materials, placed in hard loading device are studied. Multiple defects the modeled by perturbing uniform temperature within when material just starts deforming plastically to that given cosine function which assumes relative maximum values at several points block. It is found for simple deformation localizes where perturbed has minima average applied strain-rate γ 0 500 s −1 locations maxima more than 1000 . This transition occurs possibly due different thermal lengths time scales associated with work-hardening two cases. For materials near boundaries abutting = but 50,000 both initiation localization considerably delayed as compared case perturbation only one bump its center coinciding