Mutual influence of the velocity and temperature in the axisymmetric FE model of a disc brake

High energy dissipation systems with friction such as disc brakes require high and constant coefficient of friction. Its value, however, depends beside the materials of the contacting components, on the sliding velocity, contact pressure, temperature, etc. Generally the relationship of these parameters is nonlinear. In this paper an axisymmetric FE contact model was developed to study an influence of the coefficient of friction on the braking time, braking distance, maximum temperature of sliding components of a disc brake and the evolution of the sliding velocity. Computations were carried out based on the equation of motion and the boundary-value heat conduction problem of friction. The main purpose of the study was to compare the transient temperature fields of the pad and the disc, braking time, and braking distance at constant and temperature-dependent coefficient of friction. Dependencies of the coefficient of friction on the temperature and the contact pressure were adopted from experimental measurements and implemented to the FE model of a brake. Temperature and wear evolutions were presented and relevant correlations were discussed.