Surface Contact Analysis Model of Disk Brake Squeal

Abstract

A surface contact analysis model was developed to investigate the dependence of the sound pressure level and squeal frequency on the thrust pressure in contact region. This dependence was hypothesized to be caused by the dependence of the contact stiffness between the disk and pad on the thrust pressure. To examine the influence of contact stiffness on squeal, the surface contact analysis model uses distributed springs (creating contact stiffness) to connect the disk and pad. The dependence of the contact stiffness on the thrust pressure causes coupling of the disk and pad motions, and instability in this coupling generates squeal. The analysis results are in good agreement with experimental observations that the disk has translational motion while the pad has both translational and rotational motions. The contact stiffness increases along with the thrust pressure, the rotational rigidity of pad increases. As a results, the squeal frequency increases. This report clarifies that the dependence of contact stiffness on thrust pressure cause both squeal generation and dependence of squeal frequency on thrust pressure.