A slip line field analysis of the transition from local asperity contact to full contact in metallic sliding friction

Abstract

Under normal well-lubricated sliding conditions the contact is at the tips of asperities and the real area of contact is many times smaller than the apparent area of contact. When the lubrication is poor or the normal pressure between the contacting surfaces is very high the real area of contact approaches and in the limit equals the apparent area of contact. The purpose of this paper is to investigate the transition between these two extremes. The investigation is made using rigid-perfectly plastic slip line field theory and the paper concludes with a consideration of how real material properties such as strain hardening might be expected to modify the results obtained.