Behavior of Elastic-Plastic Rough Surface Contacts as Affected by Surface Topography, Load, and Material Hardness

Surface roughness plays an important role in affecting friction, wear, and lubrication of contacting bodies. A small change in the distribution of the asperity heights and widths can have a significant effect on the performance variables which include the real area of contact, the average gap, and the average asperity contact pressure. A series of contact simulations were conducted in order to investigate the effects of the surface topography, material hardness and load on the deformation behavior of the rough surfaces. These surfaces were numerically generated by computer and varied widely in statistical roughness properties, ranging from isotropic to strongly anisotropic. The current simulations took into account the elastic-plastic deformation behavior of the asperities. Using the contact simulation results, the performance variables were curve-fitted to convenient analytical formulas as functions of the surface roughness parameters, material hardness, and load.