A Comparison between Stationary and Dynamic Wear Tests of Brake Pads

Investigations of wear and wear dust behavior of brake systems are increasingly becoming the focus of research activities in science and industry. Environmental protection as well as health and economic aspects play a driving role in this context. In contrast to these important issues, the wear behavior of brake pads is still poorly understood. Due to the different material compositions of brake pads, it is also very difficult to gain universally valid insights, even when testing under stationary conditions. In previous publications, it was already identified that the friction history or a dynamic load collective can lead to different wear rates despite the same idle work. This was demonstrated by means of a multitude of real driving profiles and decreasing velocity profile measurements using the Automated Universal Tribotester at the Institute of Dynamics and Vibrations. The results of the investigations accordingly raised new questions, which will be addressed here. In addition, the knowledge gained here should serve as a metrological basis for the mathematical description of wear processes in the boundary layer of brake systems in the future. For this purpose, tests are carried out on the AUT with further load profiles on different brake pads. The results of these systematically performed measurements allow a step-by-step comparison of the wear results and friction coefficients as well as the surface topographies. This, in turn, makes it possible to establish a link between the results of the previously performed stationary wear procedures and real driving profile measurements, which leads to a better understanding of the wear behavior of brake pads and its influencing factors.