Effect of wear on frictionally excited thermoelastic instability: A finite element approach

A finite element model for the effect of wear on thermoelastic instability (TEI) is developed by combining the equations of thermoelasticity, the classical wear law, along with the conforming contact conditions. The method is based on a two-dimensional, frictional sliding model with a bimaterial interface and a simplified geometry of finite thickness. An assumption of the solution in the perturbation form leads to a quadratic eigenvalue problem. The existing analytical solutions for two half planes are employed to validate the numerical solutions for several representative scenarios, including a limiting case in the absence of wear. The analytical solutions are also sought for the special cases when one of the materials is a nonconductor and when the two materials are identical, for the purpose of comparison. In general, good agreements between the numerical and analytical approaches have been obtained. However, the discrepancies exist when the wear rates of the two materials are close to each other and when the wear rates are significantly greater than the critical rate. It is confirmed through this study that wear may suppress or amplify the effect of TEI depending on the thermomechanical properties of the materials, which is consistent with the recent research findings on the same topic via an analytical approach.