FE ANALYSIS OF BRAKE PAD SURFACE TEMPERATURES IN FRICTION BRAKING

摘要

Temperatures generated at the contact interface between the rotor and stator during friction braking have a strong influence on vehicle performance in terms of safety and driving comfort. Understanding the factors that affect the interface temperature will help in further refinement of the vehicle braking system design as well as adding to the scientific understanding of the subject. In this paper, maximum temperatures at the friction surface of a disc brake pad are studied using Finite Element Analysis (FEA) techniques. Thermal boundary conditions have been designed to represent the geometric and physical nature of the pad contact surface, which is non-smooth and non-homogeneous with a complicated microstructure. Using a 'Design of Numerical Experiment' (DoNE) approach, several important parameters, viz. the thermal conductivity of the friction material, the surface contact area ratio, and the pattern of the real contact area distribution, have been investigated. The results show that, compared with other parameters studied, the thermal conductivity of the friction material has the most influence on the pad maximum temperature. The results also show that the contact area ratio has a strong effect on interface maximum temperature, and confirms the findings reported previously that the maximum temperature decreases as the contact area ratio increases in a non-linear manner (1). The findings from this work could potentially have great significance in the optimization of friction braking systems in terms of mechanical design as well as friction material design. As an example, the FE analysis of introducing a groove into brake pad design indicates that the groove has little effect on increasing maximum temperature during braking, but improves the heat dissipation during and after braking.