three-dimensional modeling of strain localization in cosserat continuum theory

in this paper, a higher order continuum model is presented based on the cosserat continuum theory in 3d numerical simulation of shear band localization. as the classical continuum models suffer from the pathological mesh-dependence in strain softening models, the governing equations are regularized by adding the rotational degrees-of-freedom to conventional degrees-of-freedom. the fundamental relations in three-dimensional cosserat continuum are presented and the internal length parameters are introduced in the elasto-plastic constitutive matrix to control the shear bandwidth. finally, the efficiency of proposed model and computational algorithm is demonstrated by a 3d strip in tensile. a comparison is performed between the classical and cosserat theories and the effect of internal length parameter is demonstrated. clearly, a finite shear bandwidth is achieved and the load-displacement curves are uniformly converged upon different mesh sizes.