An Investigation of the Effect of Enrichmental Functions in Extended Finite Element Method

In this study، the extended finite element method (XFEM) was used for modeling 2-D cracks in order to investigate the significance of the crack tip functions in the enrichment procedure. Two codes were prepared to simulate fracture of plane problems using constant strain triangle (CST) element and 4-node quadrilateral (Q4) element. Considering these elements، new and simple schemes were proposed for enrichment procedure. The stress intensity factors (SIF) for several benchmark problems were calculated، using the J-integral and the interaction integral methods. The results show that the elimination of crack tip functions has no noticeable effect on the accuracy of the computed stress intensity factor (SIF) for plane problems. It was also shown that the interaction integral method is more efficient than the J-integral method for computation of SIF in such problems.