Transient thermal response near dynamically-loaded cracks during dislocation generation

Abstract

As a step in considering thermal effects prior to dynamic fracture or the development of fully-plastic crack edge zones, a transient 2-D study of edge dislocation generation near cracks in a fully-coupled thermoelastic solid is considered. Dynamic loading is provided either by SV-wave diffraction or tension, and no heat sources are imposed upon the solid. Despite the existence of characteristic lengths in the governing equations, exact solutions to the required mixed boundary/initial value problems are obtained in the multiple transform space, and time transforms extracted by an inversion process similar to the used in classical wave propagation. From them, the temperature changes at the dislocation edges for short times after generation are developed. These show that dislocation motion and dislocation-crack interaction produce constant temperature changes that are small. However, the results for mirror pairs separating at low speeds suggest that, as dislocation arrays form in the process of plastic zone development near the crack edge, the temperature increases could well become important.