The Coupled Thermoelastic Transversely Isotropic Bimaterial: Interface Crack Extension

Abstract

A semi-infinite crack grows at a constant subcritical speed along the interface of rigidly bonded, dissimilar transversely isotropic, coupled thermoelastic half-spaces. Shear and normal loads that move on the crack faces drive the process. A dynamic steady state of plane strain is considered. Robust asymptotic full-field solutions for the related problem of translating interface disturbances are first obtained. These lead to coupled singular integral equations for the crack problem that are solved analytically. Expressions for the crack opening components and discontinuity in temperature between crack faces, the traction and temperature change ahead of the crack, and debonding energy rate are presented. These show that the critical crack speed is the minimum of the two Rayleigh speeds and, if it exists, the Stoneley speed. The case of zinc bonded to a thermally inert rigid solid is examined, and calculations for interface temperature change and debonding energy rate given. Apart from any fracture criterion, these parameters show sensitivity to crack speed and to the extent which compressive crack face loading dominates shear loading. Indeed, interface temperature change may decrease in magnitude with crack speed when shear loading dominates.