In this work, extended finite element method (XFEM) is used to simulate the fracture mechanics problems of part-through semi-elliptical circumferential crack in functionally graded pipe and pipe bend. Part-through semi-elliptical circumferential crack present in functionally graded pipe and pipe bend at different location has been subjected to internal pressure. Higher order shape function is used to model the crack with level set functions. The inner surface of the functionally graded pipe/pipe bend contains 100% steel alloy and outer surface contains 100% alumina ceramic. The material property gradation is followed by exponential law from inner surface to outer surface of the pipe and pipe bend in radial direction. Domain-based interaction integral approach has been used to determine the stress intensity factor at different location of the crack front.