Abstract: A new elastic-plastic model for the contact of rough surfaces is presented. The model is developed based on contact mechanics and the assumption that the transitions from elastic, through elastic-plastic, to fully plastic deformation of a contacting asperity is continuous and smooth. The deformation behavior of a single contacting asperity is firstly modeled in detail, particularly, for the elastic-plastic deformation. The contact between the two rough flat surfaces is then modeled by using probability theory. The model developed is compared with the GW elastic model and CEB elastic-plastic model on their predicted real contact area and mean separation for a wide range of contact load and plasticity index. It is shown that the present model predicts larger real contact area and smaller mean separation than GW model under the same contact load and plasticity index. Besides, the difference of the predicted results based on the present model and GW model increases with the contact load and plasticity index. The comparison results strongly indicate that the present model is consistent with ex-perimental observation and physical intuition, and is more rea-sonable in describing the contact behavior between rough sur-faces.

Key words: Asperity, Contact model, Elastic-plastic, Rough surfaces