VARIATION OF STRESS INTENSITY FACTOR AND CRACK OPENING DISPLACEMENT OF SEMIELLIPTIC SURFACE CRACK

In this paper a singular integral equation method is applied to calcul ate the stress intensity factor along crack front of a 3D surface crac k. Stress field induced by body force doublet in a semi infinite body is used as a fundamental solution. Then the problem is formulated as a n integral equation with a singularity of the form of r(-3). In solvin g the integral equations, the unknown functions of body force densitie s are approximated by the product of a polynomial and a fundamental de nsity function; that is, the exact density distribution to make an ell iptical crack in an infinite body. The calculation shows that the pres ent method gives the smooth variation of stress intensity factors alon g the crack front and crack opening displacement along the crack surfa ce for various aspect ratios and Poisson's ratio. The present method g ives rapidly converging numerical results and highly satisfactory boun dary conditions throughout the crack boundary.