Multiscale thermomechanical analysis of sliding rings from short-time transients to steady-state

In order to better understand the performance of clutches, brakes and seals, there is a need to study the multiscale thermomechanical interactions that occur across rough interfacial sliding contacts. While the full three-dimensional problem is at present somewhat beyond reach from a computational standpoint, we can gain some insight into the problem by examining the more idealized axisymmetric case. Here we develop a transient coupled thermomechanical boundary element method to investigate the behaviour of sliding rings with axisymmetric roughness. By incorporating our recently developed fast convolution algorithm, we are able to consider the spatially and temporally localized response at asperity-level contacts, along with the evolution toward a global component-level steady state. In particular, we investigate behaviour for the sliding ring problem by considering surface profiles that incorporate axisymmetric roughness over several orders-of-magnitude. One of the most interesting findings that emerge from these simulations is the development of roughness-dependent steady-state shapes. Details of the short-time transient interactions are found to significantly affect the long-term component level response. This suggests that one may be able to control overall component deformations through the careful specification of surface profiles.