Title: Disc brake squeal noise generation: predicting its dependency on system parameters including damping

Authors: S.W.E. Earles, P.W. Chambers

Addresses: Mechanical Engineering Department, King's College London, UK. ' Ford Motor Company Ltd., Technological Research Department, Research and Engineering Centre, Essex, UK

Abstract: The concept of the mechanism of disc brake squeal noise generation being a |kinematic constraint| or |geometricallv induced| instability is extended to include pad support and disc damping. A dynamic analysis is presented of a double-pin and disc system and the conditions for unstable oscillatory motion to occur are detailed. It has been shown previously that there is a good correlation between the occurrence of squeal noise and the predicted unstable states. Illustrations are given of the effects of varying, the system parameters, of having dissimilar pins reacting on the disc, and of including pin support and disc damping. From the wide range of possible system parameter combinations, producing many and varying effects on the size motion to occur is that one or bath of the pins has a negative (digging-in) angle of orientation to the disc surface within the range 0 < θ < tan^-1μ; sufficient conditions depend on the magnitude of the system parameter. Stable motion may be obtained by using dissimilar pin orientations, having a large disc mass or high pin torsional stiffnesses. Increasing The disc damping has little effect on the area of the unstable region, but substantially reduces the instability magnitude. Varying the pin torsional damping reduces the unstable region, but has little effect on the instability magnitude.

Keywords: brake noise; brake squeal; disc brakes; disc damping; vehicle noise; vehicle design.

DOI: 10.1504/IJVD.1987.061217

International Journal of Vehicle Design, 1987 Vol.8 No.4/5/6, pp.538 - 552

Published online: 25 May 2014 *

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