A Generalised Asperity-Based Friction Model

Despite considerable research effort, the use of physics-based modelling to predict frictional behaviour is still a debatable question in modern tribological research. This article presents a dry-friction model, based on physical phenomena such as adhesion, elastic-plastic contact and deformation. This contribution offers a means to simulate all kinds of frictional behaviour that is observed in experimental research. The contact of two bodies through their surfaces is transformed into the contact of a body that is provided with asperities and containing material and geometrical information of both of the mating surfaces, and a counter profile, holding solely geometrical information. The local adhesion between the asperity tips and the counter profile, together with the elastic-plastic behaviour of the asperities themselves, form the basis for this model. The simulation results show qualitatively good agreement with experimental study. Friction and contact phenomena such as normal creep, increasing static coefficient of friction with increasing dwell time, pre-sliding hysteresis with nonlocal memory, Stribeck and viscous effect, frictional lag, stick-slip and dynamical oscillations are revealed by this model. Furthermore, future improvement and refinement of the model is possible (and ongoing) so as to incorporate lubrication and asperity wear.