DYNAMIC STRESS INTENSITY FACTORS FOR PERIODICALLY SPACED COLLINEAR ANTIPLANE SHEAR CRACKS BETWEEN DISSIMILAR MEDIA

Presented in this work are the Mode III dynamic stress intensity factors K3 for the scattering of anti-plane SH-waves by a periodic array of cracks that lie on the dividing line of two dissimilar media. Formulation is based on the crack opening displacement of a single interface crack by application of Fourier integrals. The resulting boundary integral equation is solved by the Galerkin method. Variations of the crack tip stress intensity factor with wave length are studied as the crack spacing, dissimilar material moduli ratio and incidence angle are varied. In general, the K3-factor increased with increasing modulus of the medium in which the incident wave is applied and with decreasing distance between the cracks as expected. It also peaked at normalized wave length of approximately equal to unity when the cracks are spaced sufficiently far apart.