Multi-Scale Contact Localization and Dynamic Instability Related to Brake Squeal

Abstract

Friction-induced vibrations (brake squeal) produced during braking applications have been one of the major problems in the transportation for many years. It can be the most troublesome for passengers because of its high frequency and acoustic pressure. The role of frictional contact surface geometry on the occurrence of squeal was investigated recently by some researchers. However, it has never been systematically studied at different scales simultaneously. Contact localizations are induced on the one hand by macro effects such as thermal dilatation (macroscopic scale) and on the other hand, by the heterogeneity of third body (tribolayer) generated by friction (mesoscopic scale). The aim of this paper is to investigate the effect of contact localization at both scales through stability analysis on a simplified pad on disc system. The model has been developed numerically by the finite element method (FEM) to introduce a non-uniform contact at macroscopic and mesoscopic scales. The results showed a strong dependency between squeal frequencies and effective contact zone at macroscopic and mesoscopic scales for the investigated configuration. Especially, it is found that squeal frequencies depend on the contact area at a macroscopic scale whereas the probability of occurrence of squeal frequency strongly relies on mesoscopic contact distribution.

Contribution Analysis of Assembled Brake System to Reduce Squealing

“…A contribution analysis of the assembled brake system was conducted using the obtained spectral response vectors for each subpart. The theoretical background was the component contribution using the response spectrum data under the selected excitation situation [11,12,19,20]. Previous studies have performed a contribution analysis on complex brake systems over squealing noise problems.…”

“…Recent studies have focused on the brake problems related to squealing. Juraj et al [18] evaluated the influence of damping variations in the brake pad and disk using an FE model, and Van-Vuong et al [19] focused on the effect of multiscale contact localization at a simplified pad on a disk system. Grégoire et al [20] evaluated the efficiency of the double modal synthesis method in predicting squealing, and Arn et al [21] calculated the friction coefficient of the brake system from a microscale model and transferred it to a macroscale multibody simulation.…”