Effect of interfacial contact conductance on thermo-elastic response in a two-layered material heated by ultra-fast pulse-laser

Abstract

The thermal stress field of a two-layered material in a semi-infinite domain subjected to rapid laser heating at the front surface is solved. The interfacial contact conductance, the reciprocal of thermal resistance, existing at the interface is included in the analysis. The dual-phase-lag model coupled with linear theory of thermo-elasticity is applied to investigate the lagging behaviour of the two-layer material. The mathematical procedure of this study is complex and lengthy. At first, the Laplace transform is applied to the governing equations. The resulting second-order ordinary differential equations are then converted into a system. This leads to an eigenvalue problem. Finally, the thermal and thermo-elastic solutions can be obtained by the inversion of the Laplace transform. The thermal and thermo-elastic mechanisms are examined by a series of parametric studies. It is found that the thermal and thermo-elastic fields change dramatically in the neighbourhood of the interface during the very early stage of the heating process even though the thermal resistance is extremely small (as small as 10−9m2 K W−1). In order to eliminate the mechanical failure, the thermal resistance existing at the interface should be as small as possible.