Robustness of Disc Brake Systems Regarding Squeal

Despite the efforts in research and development of brake systems there still is a lack of procedures to evaluate the robustness of these systems with respect to friction induced vibrations during the development process. Hence, the identification of the modal properties and their characteristics using experimental methods becomes even more important. Experience shows that these modal properties can change easily due to variations in operating conditions or due to manufacturing tolerances. This work compares existing approaches to define a brake system's robustness regarding squeal. Moreover it shows experimentally the strong dependence of the system's resonance frequencies and modal damping values to slight changes in operating conditions. Consequently, a new approach is developed, in order to allow a modal analysis of a complete brake system with its' inherent robustness. The results of this study investigating the influence of different operating conditions on the modal properties are shown and these are discussed with respect to the system's robustness.