On the mechanisms, growth, amplitude and mitigation of brake squeal noise

Prediction and Suppression of Chaotic Instability in Brake Squeal

“…A reduced two mode brake squeal model consisting of two autonomous coupled nonlinear second order systems with a nonlinear friction law is first described [18]. Closed form analyses to predict the local instability occurrence, growth and limit cycle amplitude of brake squeal are then described in section 2.2.…”

“…The friction behaviour and parameters are governed by the contact mechanics which transfer friction forces and couple with the dynamics of the dominant modes of vibration of the brake system. If the interaction is unstable, the resultant brake system vibrations grow into a squeal limit cycle which in turn creates noise [18], [19]. The main aim of this paper is to investigate and quantify when the squeal limit cycle breaks up into chaotic motion.…”

“…North [8] identified the mechanism of mode coupling in automotive brake squeal, analogous to 'binary flutter', and Hoffman [9] performed a reduced model numerical analysis to provide important mechanistic insight and the effects of damping [10] [21]. The relationship between spragging and mode coupling was solidified in [18] where spragging of the dynamic modes was identified as an important condition for mode coupled squeal [18]. Complex eigenvalue analysis can be used to numerically predict brake squeal mode coupling in complex geometries, although recently an analytical solution for a reduced two mode system has been identified [18].…”

“…The relationship between spragging and mode coupling was solidified in [18] where spragging of the dynamic modes was identified as an important condition for mode coupled squeal [18]. Complex eigenvalue analysis can be used to numerically predict brake squeal mode coupling in complex geometries, although recently an analytical solution for a reduced two mode system has been identified [18]. Simplified test rig results have confirmed that mode coupled squeal primarily occurs due to two distinct modes with closely spaced natural frequencies [22].…”

“…A comprehensive FEA and experimental investigation of a 3kHz squeal in a real full brake system, by Park [15], is used for verification in this paper. Recently, a closed form prediction for the occurrence, growth and amplitude of brake squeal was identified [18], but chaos was not investigated.…”