An Efficient Approach to Estimate Critical Value of Friction Coefficient in Brake Squeal Analysis

Abstract

Automotive brake squeal generated during brake applications has become a major concern in automotive industry. Warranty costs for brake noise related complaints have been greatly increasing in recent years. Brake noise and vibration control are also important for the improvement of vehicle quietness and passenger comfort. In this work, the mode coupling instability mechanism is discussed and a method to estimate the critical value of friction coefficient identifying the onset of brake squeal is presented. This is achieved through a sequence of steps. In the first step, a modal expansion method is developed to calculate eigenvalue and eigenvector sensitivities. Different types of mode couplings and their relationships with possible onset of squeal are discussed. Then, a reduced-order characteristic equation method based on the elastically coupled system eigenvalues and their derivatives is presented to estimate the critical value of friction coefficient. The significance of this method is that the critical value of friction coefficient can be predicted accurately without the need for a full complex eigenvalue analysis, making it possible to determine the sensitivity of system stability with respect to design parameters directly.

Subcritical flutter in the acoustics of friction

“…This is more efficient for describing the deformation of the spectral mesh, e.g. the veering and merging of eigenvalue branches (Leissa 1974;Perkins & Mote 1986), than the sensitivity analysis of simple eigenvalues by Yang & Hutton (1995), Vidoli & Vestroni (2005) and Huang et al (2007).…”

Analytical formulation of mode-coupling instability in disc–pad coupled system

“…Chowdhary et al [13] developed an analytical disc-pad coupled model and showed that the modal stability boundary is associated with mode-veering. Huang et al [14,15] determined the relationship between mode-coupling and mode-merging through the eigensensitivity analysis. They also generalized the necessary conditions for modal instability by means of an eigenvalue perturbation method.…”

How to Play a Disc Brake: A Dissipation-Induced Squeal

“…The deformation of the spectral mesh near the double eigenvalue at due to combined action of gyroscopic forces and external friction is described by the expression, following from (48) and (49) in 0 : /( S P r , except for the vicinity of the node of the spectral mesh, where the real parts rapidly tend to zero. This behavior agrees with the results of numerical calculations of [13].…”

“…This mechanical system produces sound due to transverse vibrations of a rotating annular plate caused by its interaction with the brake pads. Despite intensive experimental and theoretical study, the problem of predicting and controlling the squeal remains an important issue [10,16,19,21,23,34,42,43,48,49]. Significant but still poorly understood phenomena are squealing and barring of calender rolls in paper mills causing a noise and reducing the quality of the paper [30].…”