Bridged interface cracks in anisotropic bimaterials

The bonding strength between dissimilar materials in composites is often re latively weak. Interface debonding and cracking are of common occurrence. A s an effective method to minimize such failures, fibre stitching is used to enhance the bonding strength when joining layers in polymer composites. Wi th the presence of the reinforcing fibre, the overall elastic response for each component of the composite is, in general, anisotropic. This paper inv estigates the elastic behaviour of bridged interface cracks in anisotropic bimaterials. From the equilibrium of the interface crack, a system of Cauch y integral equations for the required distributed dislocation density is ob tained. When the bridging force depends linearly on the crack-opening displ acement, explicit solutions are given in terms of a series of Jacobi polyno mials. For illustration, a bridged interface crack in isotropic bimaterials is examined in detail. Results suggest that bridging fibres effectively en hance the toughness of the composite. When the bridging force increases, th e effect of interface mismatch becomes insignificant, being overshadowed by the effect of the bridging forces.