On the Adaptive Computation of Shear Bands in Frictional Geomaterials

In frictional geomaterials, shear bands occur as a result of local concentrations of plastic strains in small bands of finite width. Since in practice as well as in numerical simulations both the location of the onset and the direction of shear bands are generally unknown, time- and space-adaptive methods are an excellent tool to detect and to solve shear band problems. In the present contribution, the ill-posedness of the numerical computation of shear band phenomena is overcome by extending the standard continuum mechanical approach by the inclusion of micropolar degrees of freedom in the sense of the Cosserat brothers.