Chilbule, C., Phadke, S., Kulkarni, R., and Raajha, M., "Mitigating the Brake Squeal Noise Occurrence of Car Disc Brake through Modification of Caliper-Bracket," SAE Technical Paper 2017-26-0218, 2017, doi:10.4271/2017-26-0218.
As an automobile brake manufacturer, brake noise always been a prime concern as it define the degree of customer satisfaction and warranty claim. Brake squeal is a concern in the automotive industry that has challenged many researchers and engineers for years. In case of disc brake, brake-squeal (1 to 16 kHz) occurrence is predominant than the any other types of brake-noise (i.e. moan, grown, judder etc.), since squeal is a friction induced, self-excited, and self-sustained phenomenon from a nonlinear dynamics viewpoint. Due to the complexities involve squeal mechanism is not well understood yet, hence makes it one of the unresolved brake Noise, Vibration, and Harshness (NVH) problem till this date. Since squeal is a high-pitched and tonal noise, therefore it is very annoying and getting more attention by occupants. Brake squeal can occur at any temperature and with or without the presence of humid condition and therefore highly unpredictable. However, it is state-of-the-art to provide the warranty based on confidence build up after the extensive testing.The intention of this analysis is to show that the caliper-bracket’s resonant frequencies contribute to the generation of brake squeal too, and one need to consider bracket’s harmonic characteristics during the designing to mitigate squeal occurrence in actual application. If it is not possible to get rid out of squeal via modification in friction pad geometry, rotor etc. within given constrains, this methodology will help to mitigate it. As it depends on various parameters such as contact mechanism, nonlinear dynamics and vibration, acoustics, and tribology. The actual testing has been done on NVH-inertiadynamometer and presented that the given modification on bracket alone mitigate the squeal occurrence by 97% without touching the other parameters of disc brake.