The effect of external grit particles on brake squeal noise of commercial brake pads

Abstract

Brake squeal has been a persistent quality issue for the automotive industry and brake suppliers. Large efforts have been made in order to understand squeal occurrences and ultimately to provide solutions for reducing it. However, due to the complex nature of brake squeal and wide frequency range in which it occurs, it is difficult to identify the possible sources of squeal excitation produced by a disc or drum brake assembly. It is, therefore, the attempt of this paper to observe the effect of external particles on the squeal noise of two different commercial brake pads. In doing so, a series of brake dynamometer tests will be conducted with at least 100 braking applications at various operating conditions for each brake pad. Two different types of external particles, namely road grit and silica sand with a size between 100 to 200 μm will be used and fed into the disc brake end corner. Brake squeal occurrences will be captured using accelerometers and a microphone. Those results will then be compared with the test results without external particles. The results shows that the squeal occurrence, the pressure, speed, temperature, and frequency level is decreased significantly with the presence of external grit particles.