特異積分方程式による自由表面近傍のだ円形内部き裂の解析

抄録

In this paper, a singular integral equation method is applied to calculate the distribution of stress intensity factor along crack front of an elliptical internal crack near the free surface. The stress field induced by the force doublet in a semi-infinite body is used as the fundamental solution. Then, the problem is formulated as an integral equation with a singularity of the form of γ^-3. In the numerical calculation, the unknown functions of the density of body force doublet are approximated by the product of fundamental density function and polynomials. The numerical results show that the present method yields smooth variation of stress intensity factors along crack front very accurately even when the crack is extremely near from the free surface. The mode I, II and III stress intensity factors for an inclined elliptical crack are shown for various geometrical conditions.