Viscoelastic Circular Contact Mechanics: A Boundary Element Formulation

In this paper, a Boundary Element methodology is presented to assess viscoelastic circular contacts in steady-state conditions, when the interacting pair shows both a low and a high level of conformity. The approach is fully general, able to deal with any real viscoelastic material, with a continuous spectrum of relaxation times, and it is based on the definition of an ad-hoc derived Green's function, which captures the circular feature of the domain. At first, the conformal contact between a rigid cylindrical punch and a holed linear viscoelastic space is studied, and the viscoelastic contribution to the overall friction is analyzed; then the BE methodology is deployed to investigate the response of a polymer roller bearing operating in steady-state conditions. The assessment of such a problem is fundamental from an industrial point of view, as we show that, differently to the purely elastic case, some of the rollers in the load zone may lose contact with the raceways at certain angular speeds: this circumstance may lead to dramatic changes of the bearing capacity and, in turn, to severe consequences on the system operation.