Yielding and transient shear banding in soft jammed solids

We have designed 3D numerical simulations of a soft spheres model, with size polidispersity and in athermal conditions, to study the transient shear banding that occurs during yielding of jammed soft solids. We have analyzed the effects of different types of drag coefficients used in the simulations and compare the results obtained using Lees-Edwards periodic boundary conditions with the case in which the same model solid is confined between two walls. While load curves and velocity profiles obtained in different conditions displays some differences, the presence of a stress-overshoot and a related transient banding phenomenon are a robust feature for overdamped systems and large enough samples. We use this computational approach to investigate the microscopic origin of the flow inhomogeneities and the role played by the confinement.