An Investigation on Brake Squeal Phenomenon and the Effect of Different Parameters on its Dynamic Characteristics

This paper is concerned with the phenomenon of disc brake squeal. Brake squeal is a high frequency noise created by the car brake systems. The noise does not disturb the performance of the brake system but mainly affects the passenger’s comfort. That is why nowadays it is one of the main factors in determining the quality of the brake system. First, the reasons expressed in the literature for the source and mechanisms of generating brake squeal are presented. Next, the instability causeb by close modes is shown as a realistic basis for the onset of brake squeal. In other words, modes which are close to each other in the frequency range and have similar characteristics may merge as the friction contribution increases and creates the squeal noise. A finite element model of the Samand brake system was constructed in a commercial finite element software and then solved in several steps. Due to the complexity of the problem and presence of large number of degrees of freedom in the model, the solution is carried out by use of parallel computing. Finally, the behavior of the model is analyzed with respect to the variation of important parameters such as coefficient of friction, brake force, stiffness of the brake system and its material characteristics. The effect of slots on the pads is also investigated. It is shown that the slots can have an important role in the squeal noise suppression.