Numerical simulation of shear band localization in geotechnical materials based on a nonlocal plasticity model

摘要

A new nonlocal plasticity model,which is based on the integral-type nonlocal model and the cubic representative volumetric element(RVE),is proposed to simulate shear band localization in geotechnical materials such as soils and rocks.An algorithm is developed to solve the resulting nonlinear system of equations.In this algorithm,the nonlocal averaging of plastic strain over the RVE is evaluated using C0 elements instead of using C1 elements to solve the second-order gradient of plastic strains.To obtain the average plastic strain,a set of special elements,called the nonlocal elements,are constructed to approximate the RVE.The updating of average stresses of the local element is based on the nonlocal plastic strain of the corresponding nonlocal elements.Numerical examples show that meshindependent results can be achieved using the proposed model and the algorithm,and the thickness of the shear band is insensitive to the mesh refinement.