This paper deals with a contact optimization problem from some methodologies which have been reported up to now in order to reduce brake squeal noise and fundamentally investigates how to make the contact region or contact shape between pads and a disk rotor. At first, a finite element model is built up for the assembled brake system and a complex eigenvalue analysis is conducted. The contact surfaces between the pads and a rotor are divided into eight regions. Each region is used as a parameter to find out the better contact condition. In the case of parametric studies, however, multiple squeals can not be controlled because of the size or shape of divided region. Therefore, a new approach is proposed by using a simple model simulation. It adopts a distributed spring model as a property of contact stiffness, and calculates the sensitivity of each spring for a squeal. If the sensitivity is positive and at a high level, the corresponding spring is removed. The proposed method is applied to automobile disk brakes. As a result of several simulations, it is confirmed that the proposed method is practical.
