Modeling of the Surface Film Influence on Thermoelastic Instability During Friction of Composite Brake Discs

The paper examines the process of thermoelastic instability occurrence during unsteady friction of anisotropic disk samples in the presence of a third body film on the friction surface. This process takes place during the operation of highly loaded braking systems (in aviation and railway transport), specialized clutches of motor vehicles and in other mechanisms. The presence of surface film leads to a decrease in surface wear simultaneously with the emergence of significant nonlinearity in the wear rate. The finite difference method was used to simulate the mutual influence of wear, frictional heating, elastic deformations and the evolution of the film on the friction surface. The process of friction and wear of discs was studied taking into account the history of a series of braking events. The annular shape of surface pressures and temperatures distribution is considered. The evolution of disc wear from braking to braking for the case of the film presence was compared with the case of film absence and experimentally measured wear.