Abstract
In this paper the elastodynamic response of a penny-shaped crack located in a functionally graded material (FGM) interlayer between two dissimilar homogeneous half spaces and subjected to a torsional impact loading is considered. The shear modulus and the mass density of the functionally graded material interlayer are assumed to vary continuously between those of the two half spaces. Laplace and Hankel integral transforms are applied to reduce this mixed boundary value problem to a singular integral equation with a generalized Cauchy kernel in the Laplace domain. The singular integral equation is solved numerically and the dynamic stress intensity factor is obtained by a numerical Laplace inversion technique. The influences of the relative magnitudes of the adjoining material properties and the FGM interlayer thickness on the dynamic stress intensity factor are examined in detail.