XFEM composite failure criterion and ABAQUS implementation considering soil crack characteristics

There are a large number of tension-shear composite cracks in various geotechnical structures. However, due to the complex characteristics of soil materials, it is difficult for traditional numerical methods to accurately simulate the composite failure process of soil cracks. Considering the characteristics of soil cracks, this paper adopts a non-local weighted average stress related to soil modulus as the basis for the discrimination of crack evolution. In ABAQUS software, through the secondary development of a subprogram, the discrimination criterion of the composite failure of soil tension-shear is realized. Combing the extended finite element method (XFEM) module, the evolution process of composite cracks in soil is simulated. The comparison with ABAQUS method shows that the proposed method is more realistic in simulating soil fracture evolution and can fully reflect the influence of soil material characteristics. Finally, the effectiveness and correctness of the proposed method are verified by simulation analysis of a three-point bending beam failure case and a slope top load sliding crack failure case. It is proved that the proposed method can accurately reproduce the generation, expansion and final penetration process of cracks in the slope failure process, which provides an effective way for the fine simulation of the whole process of slope failure.