A Cellular Automaton model to describe the three-dimensional friction and wear mechanism of brake systems

The dynamics of brake systems is determined by the growth and destruction of characteristic hard, smooth and friction-intensive structures (“patches”) on brake pads. These mesoscopic structures carry a main part of the friction power and protect the softer matrix material below from wear. This equilibrium of flow is therefore correlated with the wear rate and the friction coefficient μ which has to be interpreted as a dynamic process-parameter, as recent works show. In this paper we show, how the existing two-dimensional Cellular Automaton model of the boundary layer can be extended in order to describe the topography in three dimensions. This is realized by introducing further inner system variables. With the help of measurements for pads having run under different pressure- and temperature conditions basic interactions between the external load and the surface topography can be seen. This work presents how, based on these measurements and the Cellular Automata simulations, conclusions towards the global friction- and wear behaviour of brake systems can be made.