Finite Element Model of a Fuzzy Damper for the Beam-On-Disc Setup

Brake squeal is a complicated research topic because, on one hand, it involves several disciplines, and on the other, it deals with a complex and variable system. In fact, while there is agreement in the scientific community that squeal is a dynamic instability triggered by the modal coupling between two or three modes of the system, the interaction between the dynamics of the brake apparatus, the nonlinear aspects of the contact between disc and pad, and the tribological aspects of the wear is still object of research studies. On the other hand, when dealing with remedies to squeal occurrences, one faces the problem that any solution should be effective in different operative conditions and different environments for all the commercial life of the brake; thus, the robustness of any system for squeal suppression is a key factor. For these reasons, several researchers, focused on more simple systems that exhibit the same instability mechanism, such as the beam-on-disc setup, that is a valuable benchmark to test both effectiveness and robustness of new devices to suppress squeal. This paper presents a numerical study on the effectiveness of a fuzzy damper, based on the theory of apparent damping, that can be able to suppress squeal on the beam-on-disc setup; moreover, the numerical analysis focuses on the relation between the performances of the device and its key design parameters, showing how such a device can either work as a tuned device able to suppress a specific squeal condition, or as a wide band device able to reduce the occurrence of squeal in large frequency ranges.