MODE-I INTERACTION OF A PERIODIC ARRAY OF PARALLEL CRACKS IN A FUNCTIONALLY GRADED NONHOMOGENEOUS PLANE

The mode I interaction of a periodic array of parallel cracks which ar e uniformly spaced apart in a functionally graded material is investig ated. The two-dimensional theory of nonhomogeneous elasticity is emplo yed as the basic framework. for this study. The material nonhomogeneit y is represented in terms of the spatial variation elf the shear modul us in the exponential form along the direction of cracks, while Poisso n's ratio is assumed to be constant. Formulation of the proposed mixed boundary value problem is reduced to solving a hypersingular integral equation with the crack surface displacement as a new unknown functio n. As a result, the variations of stress intensity factors are illustr ated as a function of possible range of periodic crack spacing in conj unction with the different values of the material nonhomogeneity param eter. Furthermore, crack opening displaccements are presented for vari ous geometric and material combinations.