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ABSTRCT:
For decades, it has been a challenging task for brake engineers to reduce or totally eliminate squeal that emanates from brake systems. Despite the large number of proposals that have been implemented in tackling disc brake squeal, very few solutions are totally effective to reduce or suppress it. This paper presents an approach to tackle disc brake squeal through chamfered and slotted pad. A three-dimensional FE model of an actual disc brake system is developed. The baseline FE model is first simulated using complex eigenvalue and transient analysis to predict squeal and compared to the squeal tests data obtained in the brake dynamometer. A reasonable correlation is found between these results. Then, three different pad modifications are proposed, simulated and tested. It is shown that pad with chamfers and diagonal slot can totally suppress squeal both in prediction and squeal test.
KEYWORDS:
Disc brake; Finite element; Pad modifications; Squeal; Complex eigenvalue; Dynamic transient; Brake dynamometer
CITATION:
C.L.Saw, C.G. Choong, A.R. Abu Bakar, M.R. Jamaluddin, W.M.M.W. Harujan, and B.A. Ghani. 2011. Disc brake squeal suppression through chamfered and slotted pad, Int. J. Vehicle Structures & Systems, 3(1), 28-35. doi:10.4273/ ijvss.3.1.04
1. Introduction
Over decades, brake squeal has been a major issue to vehicle manufacturers due to high warranty payouts. Akay [1] stated that the warranty claims due to the noise, vibration and harshness (NVH) issues including brake squeal in North America alone were up to one billion US dollars a year. Similarly, Abendroth and Wernitz [2] noted that many friction material suppliers had to spend up to 50 percent of their engineering budgets on the NVH issues. It is well accepted that brake squeal is due to friction - induced vibration or self-excited vibration via a rotating disc. Brake squeal frequently occurs at frequency above 1 kHz [3] and is described as sound pressure level (SPL) above 78 dB [4]. Brake squeal has been studied since 1930's by many investigators through experimental, analytical and numerical methods in an attempt to understand, to predict and to prevent squeal occurrence.
In recent years, the finite element (FE) method has become the preferred method in studying brake squeal. The popularity of FE analysis is due to the inadequacy of experimental methods in predicting squeal at the early...