Dynamic Patterning of Shear Bands in Cosserat Continuum

Abstract

Numerical simulation of patterns of shear bands in plane-strain compression tests using an elastoplastic Cosserat constitutive equation with consideration of inertia is presented. Random distribution of the material properties acts as a trigger for the localized deformation. Two types of stress-strain curves, namely strain softening and strain softening followed by strain hardening, are investigated. The characteristic of the stress-strain curve is found to be crucial for the patterning of shear bands. While the calculations with a stress-strain curve with solely softening yield only one single shear band, a flock of shear bands can be obtained with a stress-strain curve with softening followed by hardening. Benefited from a characteristic length provided by a Cosserat elastoplastic constitutive equation, the dependence of calculations on the mesh size is avoided.