Modal Coupling and Its Effect on Brake Squeal

More evidence has been found that rotor in-plane mode(s) and out-of-plane mode(s) alignment and coupling are the primary and inherent root cause for a disc brake to generate squeal at high frequencies. Eight different vehicles with different rotors have been tested considering known squeals. It has been found that the squeal frequencies are at the rotor in-plane mode(s) and out-of-plane mode(s) alignment and coupling frequencies. Rotor modal test results, vehicle squeal frequencies, and CAE operational simulation are presented.