Boundary element analysis of thermal stress intensity factors for cusp cracks

Abstract

In case that the body with a cusp crack is under uniform heat flow, thermal stress intensity factors are calculated by using the boundary element method with a linearized body force term. The crack surface is under an insulated or fixed temperature condition and the types of cracks are symmetric lip and airfoil cusps. Numerical values of thermal stress intensity factors for Griffith cracks in finite bodies and cusp cracks in infinite bodies are proved to be in good agreement within ± 5% when compared with the previous numerical and exact solutions, respectively. The thermal stress intensity factors for symmetric lip and airfoil cusp cracks in finite bodies are calculated about various effective crack lengths, configuration parameters, and heat flow directions. With the same crack surface thermal boundary conditions, heat flow directions and crack lengths, there are no appreciable differences in variations of thermal stress intensity factors for symmetric lip and airfoil cusp cracks. The signs of thermal stress intensity factors for each cusp crack are changed with each crack surface thermal boundary condition.