Control of Brake Squeal Using Shunted Piezoelectric Pads

Brake squeal phenomenon poses serious challenges to the automotive industry due to its technical complexity and the pressing need for mitigating its undesirable effects. More importantly, brake squeal causes significant customer dissatisfaction and adversely affects the subjective quality of the vehicles. These effects have substantial economic impact on the automotive industry. Furthermore, it is essential to properly treat the brake squeal problems in order to avoid unexpected catastrophic failure of the brake system. In this paper, it is proposed to mitigate the brake squeal problems by providing the brake pads with piezoelectric patches which are shunted by properly tuned electric networks. The shunted piezoelectric pads offer a unique ability to convert the mechanical energy induced by the brake squeal into electrical energy which can be dissipated into the network in order to enhance the damping and stability characteristics of the brake system. Accordingly, it is envisioned that the proposed approach would enable the disc brake systems to operate over broad ranges of operating parameters without experiencing the adverse effects of brake squeal. The proposed system is modeled by a simple two Degree-Of-Freedom (DOF) disc brake model. The structural DOF are integrated with the constitutive model of the shunted piezoelectric network in order to predict the threshold of brake squeal. The stability limits of the proposed brake system are established as a function of the design parameters of the shunted piezoelectric network. Numerical examples are presented to demonstrate the effectiveness of the proposed system in expanding the operating range of the brake system without experiencing squeal problems. Application of the proposed system to a distributed disc brake system model is a natural extension of the present work.