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

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). • Adiabatic Shear bands are studied numerically through the collapse of thick-walled cylinders. • A perturbation distributed on a Voronoi pattern is imposed to trigger instability • An algorithm has been developed to identify individual bands in simulations. • Several draws of Voronoi cell structure are conducted to investigate the variability in shear bands pattern. [ABSTRACT FROM AUTHOR]