Mixed-mode interaction of two offset interfacial cracks in bonded dissimilar half-planes with a functionally graded interlayer

• Two offset interfacial cracks in bonded dissimilar media with a graded interlayer were considered.
• An amplifying or a shielding effect vs. various geometric and material parameters was examined.
• The shielding behavior was shown to be more pronounced for the crack on the stiffer side.
• The probable incipient cleavage angles of the original cracks were also provided.

The problem for bonded dissimilar half-planes with a functionally graded interlayer weakened by a pair of two offset interfacial cracks is investigated, within the framework of linear plane elasticity. The Fourier integral transform method is employed and the formulation of the current crack problem is reduced to a system of Cauchy-type singular integral equations. In the numerical results, parametric studies are conducted so that the variations of mixed-mode stress intensity factors vs. offset crack distance are illustrated, elaborating several unique and salient features regarding the singular crack interaction strongly affected by the material and geometric configurations of the bonded system. Further addressed is the quantification of probable cleavage angles for the incipient kinking of the original cracks.