The Effects of Surface Roughness and Topography on the Contact Behavior of Elastic Bodies

The real area of contact, average gap, and mean asperity contact pressure are important variables for understanding friction, wear, and lubrication in contacting systems. They are known as “performance variables.” Contact simulations were conducted for a wide range of surface topographies and an extensive amount of information was generated. Using this information, the performance variables were curve fitted and convenient mathematical relationships were formulated. The surfaces used in the simulations were numerically generated and they varied widely in statistical roughness properties, ranging from isotropic to strongly anisotropic. The effect of surface roughness on the performance variables were studied using three parameters—composite Root Mean Square roughness (σ), autocorrelation length (λ_x*), and asperity aspect ratio (γ).