Comparison between the Extended and Conventional Finite Element Methods in Prediction of Failure Load of V- Notch Specimens under Mixed Mode Loading

V- Shaped notches are one of the most common discontinuities in engineering structures which are designed for specified engineering purposes. In order to avoid high stress concentration near the notch tip; this area is repaired by curved shapes to prevent brittle fracture. Due to changing the initial notch geometry, load carrying capacity of the new notch would be different from the initial one. In the present research, the known test specimens, so-called Brazilian disk (BD) containing curved edges made of Polymethyl methacrylate (PMMA) are considered for conducting the fracture tests at room temperature. In order to predict the fracture loads, the extended and conventional finite elements method are employed and both of the results are obtained. In the following, simulation results are compared with the experimental results and validated. According to this comparison, it is revealed that the proposed criteria based on both the extended and conventional finite elements method can successfully predict static strength of V- notch BD specimens. Meanwhile, it is concluded that using the extended finite element method (XFEM), in addition to reducing the computational costs and mesh sensitivity, is more accurate.