A closed interface crack in anisotropic bimaterials

Abstract

It is known that an interface crack between dissimilar elastic solids exhibits oscillatory behavior if the crack tip is assumed to be open with a sharp transition between bonded interface and traction-free crack surfaces [10]. For interface cracks in isotropic solids, Comninou [ 1-4] showed that the peculiar oscillatory behavior, which predicts interpenetration of the crack faces, can be fully eliminated by introducing a zone of frictionless contact between the crack faces behind the crack tip. The effects of crack face contact can not be neglected under shear and/or compression dominated loading, for in that case the contact zone size could become of the same order as the total length of a crack [3,4]. Gautesen and Dundurs [6] solved exactly the integral equations involved in the Comninou formulation. Wang and Choi [8,9] applied the frictionless contact model to interface cracks between laminated composite materials. Wu [12] attempted to apply the frictionless contact model to general anisotropic interface cracks and found that the oscillatory behavior is still present. In this report, we propose a generalized contact model which completely eliminates the oscillatory behavior for interface cracks under arbitrary anisotropy.