Thermoelastic contact instability of a functionally graded layer and a homogeneous half-plane

The conductive heat transfer between two elastic bodies in the static contact can cause the system to be unstable due to the interaction between the thermoelastic distortion and pressure-dependent thermal contact resistance. This paper investigates the thermoelastic contact instability of a functionally graded material (FGM) layer and a homogeneous half-plane using the perturbation method. The FGM layer and half-plane are exposed to a uniform heat flux and are pressed together by a uniform pressure. The material properties of the FGM layer vary exponentially along the thickness direction. The characteristic equation governing the thermoelastic stability behavior is obtained to determine the stability boundary. The effects of the gradient index, layer thickness and material combination on the critical heat flux are discussed in detail through a parametric study. Results indicate that the thermoelastic stability behavior can be modified by adjusting the gradient index of the FGM layer.

The stability boundaries as a function of thermal contact resistance R∗ for different values of the gradient index with the dimensionless thickness are presented for Type 1 material combination. Here, Q∗ is the dimensionless critical heat flux. The results indicate that we can increase the critical heat flux and change the stability boundaries by adjusting the gradient index of the FGM layer, and hence modify thermoelastic stability behavior of systems.Figure optionsDownload as PowerPoint slide