Brittle interfacial cracking between two dissimilar elastic layers: part 1-analytical development

Fracture on bimaterial interfaces is an important consideration in the design and application of composite materials and structures. It has, however, proved an extremely challenging problem for many decades to obtain an analytical solution for the complex stress intensity factors (SIFs) and the crack extension size-dependent energy release rates (ERRs), based on 2D elasticity. This work reports such an analytical solution for brittle interfacial cracking between two dissimilar elastic layers. The solution is achieved by developing two types of pure fracture modes and two powerful mathematical techniques. The two types of pure fracture modes are a SIF type and a load type. The two mathematical techniques are a shifting technique and an orthogonal pure mode technique. Overall, excellent agreement is observed between the analytical solutions and numerical simulations by using the finite element method (FEM). This paper reports the analytical development of the work. The numerical verification using the FEM is reported in Part 2 by Harvey, Wood and Wang (2015).