On the modelling of Coulomb friction

Cull, S. J. and Tucker, Robin (1999) On the modelling of Coulomb friction. Journal of Physics A: Mathematical and General, 32 (11). pp. 2103-2113. ISSN 0305-4470

Abstract

This paper analyses two different representations of Coulomb friction in the context of a dynamic simulation of the torsional vibrations of a driven drill-string. A simple model is used to compare the relative merits of a piecewise analytic approach using a discontinuous friction profile to a numerical integration using a smooth nonlinear representation of the Coulomb friction. In both cases the effects of viscous damping on the excitation of torsional relaxation oscillations are exhibited.