A dry friction model to realize stick for simulation of a dynamic system

Abstract

Friction contact occurs in most engineering problems. The friction brings about friction-induced vibration and noises which are chatter and squeal are caused by the vibration. To predict such vibrations of systems with friction accurately, the friction modeling is very important task because the dynamic behavior is dominantly governed by the friction. Coulomb friction model is the most widely known and used model. The Coulomb friction model is very useful in theoretical analysis and the model gives relatively good result. However, because of the characteristic of the Coulomb friction model, it is difficult to define the friction force for stick region. The fiiction force is neither unique nor continuous at zero relative velocity. Accordingly, it is difficult to apply the Coulomb friction model to simulation of a dynamic system. To resolve these problems, the Coulomb friction model was approximated using a spline function. The approximated friction model, however, hardly realizes stick since significant amount of slip always occurs because of the characteristic itself Therefore, the approximated friction model cannot describe stick-slip vibration and stick in simulation of a dynamic system having frictional contact accurately. In this paper, a new friction model for simulation was proposed to realize stick. The proposed friction model gave reasonably good results compared to the results obtained by using an approximated friction models. The validity and reliability of the proposed friction model were verified by comparing its results to experimental results.