Fracture analysis of an orthotropic strip with imperfect piezoelectric coating containing multiple defects

• Analytical model is presented for the analysis of a coating-substrate structures.
• Distributed dislocation technique is used to construct integral equations.
• Dislocation densities are employed to determine field intensity factors.
• Formulation is applicable for several defects with arbitrary patterns.

This paper presents an analytical model for the analysis of an orthotropic strip with piezoelectric coating weakened by multiple defects. The medium is subjected to anti-plane mechanical and in-plane electrical loading. Using the dislocation method, the problem can be reduced to a system of singular integral equations, in which the unknown variables are dislocation densities. The integral equations are of the Cauchy singular kind and are solved numerically to determine stress intensity factors at the crack tips and hoop stress on the cavity. The obtained results are analyzed to evaluate the dependence of the stress intensity factors and hoop stress on the imperfect bonding coefficient, the defect geometry and material properties of the orthotropic substrate.