An interaction integral method for calculating heat flux intensity factor with the XFEM

Abstract

The JT integral is defined to extract the heat flux intensity factor (HFIF), which is used to describe the singularity of heat flux near the tip of a crack, and the path-independence of the JT integral is theoretically proven. Based on the JT integral, the relationship between the HFIF and an interaction integral is established through introducing auxiliary field function. The extended finite element method (XFEM), which enriches the standard finite element approximation by additional functions, is utilized to solve the temperature field of a cracked structure under specified thermal boundary condition. Numerical examples of cracked plates respectively with an edge crack and a center crack are used to verify the presented method, and the method is also used to investigate the HFIF near the tip of an inclined crack and the interaction effect of two cracks on the HFIF. The presented method provides a foundation for the investigation into the crack propagation behavior of a structure under thermo-mechanical loading.