Analysis of Brake Squeal Noise using FEM Part II: Effect of Operating Parameters and Control Methods

Brake squeal noise has been under investigation by the automotive manufacturers for decades due to consistent customer complaints and high warranty costs. In most cases, the customer perceives the noise as a vehicle problem and demand having it fix by their dealer. J. D. Power surveys consistently show brake noise as one of the most critical vehicle quality measurements. Furthermore, the development of methods to predict the noise occurrence during the design of a brake system has been the target of many researchers in the last years. The complex eigenvalue analysis has been widely used to detect unstable frequencies in brake systems models. The method is fast and useful to provide design guidance, since operating parameters and control methods can be evaluated by a simulation procedure. This paper summarizes the application of the complex eigenvalue analysis in a finite element model of a commercial brake system. The effect of the operating parameters (friction coefficient, braking pressure, brake temperature) and wear on the dynamic stability of the brake system is examined. After identifying unstable frequencies and the behavior of the brake system under different conditions, the performance of some control methods are tested. Changes in material properties and the application of brake noise insulators are presented and its effect discussed.