A Study of Noise Reduction by Damping Layer Materials

Noise generation during braking is a complicated dynamic problem which automobile manufacturers have confronted for decades. Customer complaints result in significant warranty costs. More importantly, customer dissatisfaction may results in rejection of certain models and vehicles. In order to produce quality automobiles in today's marketplace, the occurrence of disk brake noise is not acceptable.

Addition of a damping layer material between the backing plate and the friction material may be used to reduce brake noise of the pads and consequently, for the brake system. Damping serves to attenuate traveling waves in the structure, so adding additional damping is a good way to reduce vibrations and noise.

In this study the use of modal analysis techniques to select brake damping layers for reduction of brake noise is considered. Several damping layer formulations have been tested using modal analysis technique. Based on the analysis, a damping layer selection has been considered. The selection of the damping layer was made by applying techniques from design of experiments. Finally, dynamometer tests and LACT tests were performed to validate the obtained results. The influence of damping layer for noise reduction for two different brake systems is presented.