Modelling of surfaces with a bimodal roughness distribution

Most contact analyses assume that the surface heights and peak (summit) hei ght distributions follow a single modal distribution, Gaussian or non-Gauss ian. However, height distributions of many surfaces follow multi-modal dist ributions. In this study, for the first time, algorithms are developed to g enerate various bimodal surfaces on the computer. Statistical analyses and contact analyses of these surfaces have been carried out. The present algor ithms are applied to particulate tapes and head-finishing processes to illu strate the effect of the bimodal distribution on the contact performance. F rom these analyses, an optimum bimodal roughness distribution is predicted for minimum friction and wear.