Investigation on the effect of mesh density and surface smoothing for real rough surfaces in contact

Abstract

Traditionally, analytical surface models have used assumptions and simplifications due to the complexity of the surface geometry. Numerical simulations have been utilized for surface analysis as computational capabilities increased. However, the assumptions and simplifications used in the analytical models still have been applied to the numerical models. M. K. Thompson developed new methods to create real measured surfaces directly in finite element program and analyzed real surface phenomena. The results of the simulations showed higher accuracy than those of idealized surface geometry, but there was some doubt about reliability. As an extension of that work, this thesis examines the effect of mesh density and surface smoothing for real measured surfaces in contact using finite element models. For the simulations, static and steady state contact between a rigid flat and a deformable real rough surface is defined. Linear elastic and bilinear elastic-plastic properties are applied as material properties. The representative results are recorded and compared to each other according to mesh refinement and asperity shape. Real area of contact, average contact pressure, and contact gap parameters are valid for this analysis and hardly affected by mesh density and surface smoothing. Maximum contact pressure and maximum equivalent stress are not reliable parameters due to hyper-sensitivity to mesh refinement. This work provides validity of the previous real surface simulation work and suggests appropriate mesh density and asperity shape for contact analysis of real surfaces.