A Generalised Asperity-Based Friction Model

Abstract

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.

Modeling Friction for Turbomachinery Applications: Tuning Techniques and Adequacy Assessment of Heuristic Contact Models

“…Realistic models, based on the integration over the whole contact surface of mechanical principles applied at the asperity level, for example [9], are the only kind which allow for a predictive contact parameter estimation. In other words, these models can be calibrated using information concerning the geometry, roughness distribution, material properties, etc.…”

“…These features, while relevant in other fields, are not typically considered in turbomachinery applications. These models belong to the larger family of heuristic models, as opposed to microscale "realistic" models where asperities and surface roughness are modeled using stochastic distributions [9].…”

Modeling and Experiment Design for Identification of Wear in a Robot Joint Under Load and Temperature Uncertainties Based on Friction Data

“…At a contact level, the surfaces' asperities can be compared to (very stiff) bristles in a brush, each of which can be seen as a body with its own dynamics connected by the same bulk [18], [19]. Because the internal friction states are not measurable, it is common to study friction in a steady state, when friction presents a static behavior.…”

Applying a population growth model to simulate wear of rough surfaces during running-in

“…Therefore, equations need to be established to reflect the changes of every local peak and valley in a rough surface. Recently, Moerlooze et al [16,17] presented a theoretical spring model to describe the asperities wear evolution in a plain contact.…”