Abstract
In this paper, a singular integral equation method is applied to calculate the stress intensity factor along crack front of a 3-D rectangular crack in an infinite body and a 3-D semi-elliptical surface crack in a semi-infinite body under mixed mode loading. The body force method is used to formulate the problem as a system of singular integral equations with singularities of the form r^<-3> using the stress field induced by a force doublet in an infinite body as fundamental solution. In the numerical calculation, unknown body force densities are approximated by using fundamental density functions and polynomials. The results show that the present method yields smooth variations of mixed modes stress intensity factors along the crack front accurately. Distributions of stress intensity factors are indicated in tables and figures with varying the shape and Poisson's ratio.
