Combining the Cosserat continuum with Breakage mechanics in a consistent thermodynamic way, offers substantial benefits to our capacity to model granular physics by accounting for both the entire grain size distribution, and its evolution. We provide an upscaling procedure that introduces material parameters accounting for the contribution of an evolving internal length representing the statistics of the entire grain size distribution. Our model requires no additional calibration relative to the same model in the classical continuum and enables us to examine the effect of grain size polydispersity and grain breakage on the thickness of shear bands and on apparent softening. By implementing the model using the finite element method, we provide an explanation for the geological formation of double cataclastic shear bands in seismogenic faults.
M2M 