Modelling and control of friction-induced vibrations

Friction-induced vibrations in technical applications are usually unwanted, as they create noise, diminish accuracy and increase wear. This article intends to give insight into basic excitation mechanisms of friction-induced vibrations and to show possible ways of avoidance. Excitation mechanisms under investigation are a friction characteristic decreasing with increasing relative velocity, fluctuating normal forces, non-conservative restoring forces and sprag slip. They are treated using mechanical models with up to two degrees of freedom. Analytical and numerical stability analysis as well as numerical time step integration is used to show the influence of model parameters on the excitation of friction-induced vibrations. In the second part of the article, measures to avoid friction-induced vibrations are presented and explained. Such measures are an increase in external damping, additional external excitation as well as active and passive vibration control.