Thermoelastic instability of functionally graded materials in frictionless contact

Abstract

This paper investigates the static thermoelastic instability between a functionally graded material (FGM) half-plane and a homogeneous half-plane under the plane strain state using the perturbation method. Two frictionless half-planes are pressed together by a uniform pressure and transmit a uniform heat flux at their interface where a pressure-dependent thermal contact resistance is taken into account. The material properties of the FGMs are assumed to be of an exponential form. The characteristic equation is derived to determine the thermoelastic instability behavior of two half-planes. The instabilities are categorized into three types based on the ratio of the material properties. The effects of the gradient index, thermal contact resistance and material combination on the critical heat flux are discussed by the parametric studies. It is indicated that the use of FGMs can improve the thermoelastic instability behavior of systems.

Thermoelastic instability of functionally graded coating with arbitrarily varying properties considering contact resistance and frictional heat

“…Their results showed that controlling a material property gradient in FGMs could lead to a significant improvement in the resistance to the contact deformation and damage [34][35][36][37][38][39]. In the past few years, the frictionally-excited TEI and static TEI of FGMs were investigated by Jang and his co-authors [40,41] and Ke and his co-authors [2,42,43], respectively. Specially, Liu et al [44] analyzed the dynamic instability of an elastic solid sliding against a functionally graded material coated half-plane without frictional heat.…”

“…Compared with our previous papers [2,42,43,45] on the TEI of FGMs, the new aspects of this paper are: (1) The main concern of these papers was placed on the static TEI of FGMs, which was induced only by the thermal contact resistance. In this paper, we discuss the coupled effect of the frictional heating and thermal contact resistance on the TEI of FGMs.…”

“…Note that many papers studied the TEI of FGMs with the thermoelastic properties varying exponentially [2,[40][41][42][43][44][45]. In their analysis, the thermal diffusivity coefficient of FGMs treated as a constant directly for mathematical convenience because it is impossible to obtain the analytical solution for the transient heat conduction equation with graded thermal diffusivity coefficient.…”

“…In previous works concerning the thermoelastic crack problem of FGMs [47,48], thermoelastic contact of FGMs [36] and TEI of FGMs [40][41][42][43][44][45], the thermal diffusivity coefficient is always treated as a…”

“…Secondly, we want to examine the error in our previous work about the TEI of FGMs [2,[41][42][43] with the thermoelastic parameters varying in the exponential form. In those works, the thermal diffusivity coefficient is treated as a constant by assuming that the gradient indices of the thermal conductivity, density and specific heat satisfy a certain relation [2,[40][41][42][43][44][45]. Here, we only consider the effect of the different form of  on the critical siding speed * V for the complex root instability since it indeed has no effect on the real root instability behavior.…”