Estimation of Fracture path in the Structures and the Influences of Non-singular term on crack propagation

In the present research, a fully Automatic crack propagation as one of the most complicated issues in fracture mechanics is studied whether there is an inclusion or no inclusion in the structures. In this study The Extended Finite Element Method (XFEM) is utilized because of several drawbacks in standard finite element method in crack propagation modeling. Estimated Crack paths are obtained by using Level Set Method (LSM) in coupling with XFEM for 2D mixed mode crack propagation problems. Also, stress intensity factors for mixed mode crack problems are numerically calculated by using interaction integral method completely based on familiar path independent J-integral approach. However, the influence of the first non-singular term (T-stress) of Williams’ stress distribution series in a cracked body is considered. Different crack growth paths are calculated for different domains with predefined notches such as edge and center cracks. In addition, predefined cracks and inclusions are implicitly defined using enrichment procedure in the XFEM framework and the effects of soft or hard inclusions are studied on crack propagation schemes. Finally, estimated crack paths under assumed conditions by using XFEM, are compared with the experimental results.