Numerical Modeling of Part-through Cracks in Pipe and Pipe Bend Using XFEM

In this work, extended finite element method (XFEM) is used to evaluate the stress intensity factors (SIFs) of a semi-elliptical part through thickness axial/circumferential crack. The pipe or pipe-bend having a crack on the outer surface is subjected to internal pressure or opening bending moment. Partition of unity approach is used to enrich the displacement approximation with the help of additional functions. To accurately model a crack, the level set functions are approximated by higher order shape functions. Domain based interaction integral approach is used to determine SIFs from XFEM solutions. The results obtained by XFEM approach are compared with the FEM solution. These results show that the location of crack and loading have significant effect on the SIFs.