Abstract
KEYWORDS – disc brake squeal, vibration, dynamic instability, friction, experiment
ABSTRACT
Today, disc brake squeal can be simulated by FE Analysis in actual disc brake system, but it is very difficult to put so many dynamic unstable solutions into stable solutions. Therefore researches for small disturbance in dynamic unstable systems are very important. In this study, the experimental set-up was developed for basic research. Disc brake squeal at 2.7 kHz was able to be triggered by the exciter force of random and sin function brake squeal frequency 2.7 kHz. Based on the theoretically analysis, it is considered that disc brake squeal trigger is influenced by friction force variation like adhesive friction and wear phenomenon and so on. It depends on friction coefficient, friction point offset, friction material Young’s modulus and its torsional spring stiffness. When the frequency of friction force variation is same as disc brake squeal of dynamic unstable frequency, disc brake squeal is caused by this trigger. It is most influenced by rectangular wave friction force variation. When the frequency of friction force variation is the 3rd order of brake squeal frequency, disc brake squeal can be triggered by pad material low torsional spring stiffness. Then friction force variation is varied from the 3rd order frequency of brake squeal to rectangular vibration of brake squeal frequency. Its rectangular vibration is considered to be adhesive friction and wear phenomena.