Generalized thermoelastic analysis of layer interface excited by pulsed laser heating

Abstract

In order to investigate the temperature and stress distribution at the interface of an elastic layer and a rigid foundation under laser thermal shock, a boundary element method is presented. The effective stress and temperature fields are calculated at the interface. The bounded layer absorbs the thermal energy from a repetitively pulsed laser in its surface plane. The pulse duration is of the order of the characteristic time for heat to diffuse across the layer thickness, and thus axial heat conduction cannot be neglected. The generalized thermoelasticity assumption based on the Lord and Shulman model on the temperature and stress distribution at the interface of an elastic layer is considered. Comparison with the classical coupled and uncoupled models are investigated. The effects of the pulse duration and layer thickness on the effective stress and temperature distribution of the layer is studied using the classical theory of thermoelasticity. It is found that for the same maximum surface temperature rise, a shorter pulsed laser induces much stronger effective stress wave front. The layer thickness, on the other hand, has minor effect on the effective stress distribution.