At&m&--In case that the body with a cusp crack is under uniform heat Bow, 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.
SEVERAL attempts have been made to determine thermal stress intensity factors (TSIFs)[l-81. Among these studies, Sumi[4] obtained the TSIFs for Griffith cracks with steady temperature distribution in finite rectangular plates by using the modified mapping collocation method. Thereafter, Emmel et a1. [5] applied the finite element method to the same model as Sumi's and compared his numerical solutions with Sumi's. Tanaka et aZ. [6] determined TSIFs for various line cracks by employing boundary element method (BEM). Sladek er a/.[?'] ~ansfo~~ area integral for body force term in BEM to line integral and calculated the TSIFs for edge cracks.
Research on TSIFs for cusp cracks under thermal loading seems to be relatively rare. One of the authors of this paper reported theoretical TSIFs [8] for cusp cracks in infinite bodies by using a complex variable approach.
In this paper, using BEM with the linearized body force term, the TSIFs for the same model as Sumi's in finite bodies as well as cusp cracks in infinite bodies are determined and compared with the previous solutions [rl, 8]. The same method is applied to obtain the TSIFs for the cusp cracks, whose surfaces are insulated or fixed to zero relative temperature, in finite bodies.