Dynamic interaction of friction and surface topography in brake systems

In brake systems the surface topography of the brake pad is characterized by an equilibrium of flow of hard patches, which are built up and destroyed, depending on the load history. Since these patches carry the main friction power, the friction coefficient itself depends on the load history, too. So the friction coefficient has to be described by differential equations instead of algebraic equations, connecting intimately the friction- and wear process. With these dynamic dependencies we are able to build up a new model, using the technique of Cellular Automata, which gives a dynamic and detailed insight into the brake pad's surface topography during the friction process.