Control of Friction by Surface Microgeometry Variation

Some models of a sliding contact of the surfaces with periodic microgeometry over a viscoelastic body are presented. The various gap conditions, such as complete contact, boundary friction, and the contact of dry surfaces with adhesive interaction, are considered. Based on the analytical or semi-analytical solutions of the periodic contact problems, the effects of the microgeometry parameters on the contact pressure distribution and the mechanical component of the friction force are analyzed for various gap and load/velocity conditions.

The main causes of energy dissipation in sliding contact of deformable bodies are hysteresis losses and adhesive interaction of the contacting surfaces (Bowden and Tabor, The friction and lubrication of solids. Part 2. Clarendon, Oxford, 1964; Kragelsky et al., Friction and wear: calculation methods. Pergamon Press, Oxford, 1982). Their influence on friction force depends on the mechanical properties of the contacting bodies and their surface layers, conditions in the gap between surfaces, operation conditions, such as applied load, sliding velocity, temperature, and environment conditions. Besides, surface microgeometry has the significant effect on friction force, particular under conditions of dry contact and boundary lubrication. In this paper some models of a sliding contact of the surfaces with periodic microgeometry over a viscoelastic base are presented. Based on the models, the dependences of the friction force on the microgeometry parameters are analyzed for various contact conditions.