The problem for bonded half-planes containing a crack at an arbitrary angle to the graded interfacial zone

The plane problem for bonded elastic half-planes containing a crack at an arbitrary angle to the graded interfacial zone is considered in this paper. The interfacial zone is treated as a nonhomogeneous interlayer with its elastic modulus varying continuously in thickness direction, Based on the use of the Fourier integral transform method and with the aid of the stiffness matrix approach, the crack problem is formulated as a system of singular integral equations for arbitrary crack surface tractions. The main results presented are the variations of mixed-mode stress intensity factors as a function of the crack orientation angle for various combinations of material and geometric parameters of bonded media in conjunction with the nonhomogeneity in the graded interlayer. The probable cleavage angles for the crack growth direction are also evaluated under the remote biaxial loading, together with the corresponding values of effective tensile mode stress intensity factors. (C) 2001 Elsevier Science Ltd. All rights reserved.