Contact behaviour of the original and substituted real surfaces

Several engineering components transfer load under sliding contact. Between two sliding bodies there are contacts over only small areas of the nominal contact area due to the surface roughness and surface waviness. The nomina l contact pressure is therefore much smaller than the real contact pressure acting over the real contact areas inside the contour contact areas. To evaluate the contact parameters (location of the real contact area and c ontact pressure distribution) different numerical methods have been used in the past decades. The latest ones can consider the real surfaces based on measured surface roughness data. The present study focuses on the characteristic features of the asperities using hemispherical, ellipsoidal and parabolic surfaces as substituting sur faces. In each case the location of the real contact area and contact press ure distribution are evaluated and compared with the results representing t he original measured surfaces. The best agreement was obtained if paraboloi des were used for substituting asperities. This technique can provide statistical type results characterising the cont act behaviour, if the substituting asperities are considered. (C) 2001 Else vier Science Ltd. All rights reserved.