Analysis of Disc Brake Squeal Using Finite Element Methods 891150
A method for determining the geometric stability characteristics of a disc brake assembly is presented. Since disc brake “squeal” noise typically occurs at unstable resonant frequencies of a system, the likelihood of disc brake squeal for a particular design can be determined. Finite element methods are used to derive the equations of motion for a brake system. Both substructuring of the system and modal representation of the components are utilized. The components are coupled together in a system model including friction coupling terms between the rotor and linings. An asymmetric stiffness matrix is the end result of the friction coupling, providing a pseudo forcing function that will excite the unstable modes of the system. A complex eigenvalue analysis provides the frequency and damping for each vibration mode. The damping values reveal which modes are unstable and therefore likely to produce squeal. Sensitivity studies are performed on several design variables to determine values where squeal is less likely to occur.