Reduction of motorcycle's drum brake squeal noise using constrained layer damping (CLD)

Abstract

Brake noise, particularly squeal is the most annoying and disturbing sound to the people, With a large number of motorcycles used in Malaysia, the level of squeal noise can be very high, especially during busy or heavy traffics due to high numbers of braking applications, Thus, this paper aims to reduce potential squeal noises generated by a rear drum brake assembly of motorcycles using constrained layer damping (CLD), A three dimensional finite element (FE) model of the drum brake assembly that consists of a drum and two brake shoes is developed and analysed, Complex eigenvalue analysis (CEA) is employed to determine stability of the drum brake assembly, where positive real parts of the eigenvalues indicate an unstable modes and its associated imaginary parts indicate an unstable (squeal) frequencies. In order to reduce squeal noise, four constrained layer damping (CLD) models have been proposed and assessed, The complex eigenvalue results show that the CLD2 and CLD4 models can fully eliminate unstable mode at a frequency of6120 Hz, while in frequency of 2051Hz the positive real part has been reduced from +222 to + 199 for CLD2 and + 182 for CLD4, The CEA results indicate that proper CLD designs can be used to reduce drum brake squeal noise in the motorcycles.