XFEM Potential Cracks Investigation using Two Classical Tests

Extended Finite Element Method (XFEM) is used in this work, first to perform the simulation of crack initiation and propagation mechanisms in plane models and then to determine the stress distribution singularities in the closest surroundings of a front fracture inserted in three-dimensional models. The essentials of XFEM is the well-known Finite Element Method (FEM) adding to degrees of freedom and enrichment functions, which serve to describe local discontinuities in the model. In XFEM, the fracture geometry is developed independent of the mesh, allowing it to move freely through the domain, without the need to adapt the mesh to discontinuity. In other words, the XFEM reproduces the discontinuity of the displacement field along the fracture, without discretizing this feature directly in the mesh. XFEM carry out the spatial discretization of two classic models in Fracture Mechanics: the single-edge-notch bending test (SEN (B)); and the disck-shaped compact tension test (CDT). The propagation criterion is based on the proportion of energy released and the stress intensity factors (SIF). The solutions provided by the XFEM numerical model indicated an excellent agreement with the results obtained from the experimental data.