Numerical simulation of strain localization based on Cosserat continuum theory and isogeometric analysis

The Cosserat continuum theory is combined with isogeometric analysis (Cos-IGA) to simulate strain localization problems of geomaterials. The results demonstrate that the numerical solution based on Cos-IGA is convergent and mesh-independent and that the Cos-IGA method can capture the initiation and propagation of the shear band as strain localization problem involved. The Cos-IGA method can also effectively alleviate the influence of mesh distortion in the shear zone, even in the case of large deformations. Further, the Cos-IGA method reduces computational cost and eliminates errors caused by geometric discretization compared with the Cos-FEA method. It suggests that the C²cubic (three-order) basis function for Cos-IGA is the best choice for simulating strain localization problems considering computational cost and convergence.