Shear bands occurrence in collapsing thick-walled cylinders: Role of user-defined perturbations

Abstract

Self-organization of multiple adiabatic shear bands (ASB) is often investigated through collapsing thick-walled cylinders (TWC). In the present work, the material behavior is described by a thermoviscoplastic constitutive law with a strain energy based failure model. Inhomogeneities in the specimen are somehow represented using Voronoi cells. In addition, a user-defined perturbation is imposed in the numerical perturbation to each Voronoi cell. Therefore, a mesh independent perturbation is obtained. Several draws of initial perturbation are considered to investigate variability in shear band patterns. The numerous realizations are analyzed through an algorithm to track and count shears bands providing statistically significant results. The influence of the failure model and perturbation parameters on shear bands number and length is studied. While short bands are affected by the size of the cells, it is shown that the self-organized pattern of developed bands is relatively independent of the imposed Voronoïcell structure. The amplitude of the perturbation affects neither the pattern nor the length of bands (within the considered range of amplitude of the user-defined perturbation).