A numerical simulation model of microscopic cleavage crack propagation based on 3D XFEM

Abstract We proposed a model of cleavage crack propagation in steel based on the extended finite element method (XFEM). In the proposed model, the geometry of the polycrystal is modeled independently from the finite element mesh, as well as the crack shape. As the fracture criterion of the cleavage crack propagation, the cleavage plane was formed on the {1 0 0} plane of the grain where the maximum normal stress was applied. As validation of the proposed model, the numerical simulation results of fracture surface morphology were compared with the SEM observation results obtained from the specimen of crack arrest test. The result shows that the proposed model can successfully simulate complicated microscopic cleavage crack propagation behaviors, such as micro-branching and wraparound of cracks.