Mechanism And Control Of Disc Brake Noise

As automotive technology which about noise and vibration control continuesto bloom, the main source of noise and vibration performance has been greatlyimproved. Minor noise and vibration sources for automotive quality have becomeincreasingly prominent. The brake noise generated during braking has drawnincreasing attention. But solving brake noise and vibration problems is not thateasy. Therefore, car manufacturers start to attach great importance on how toreduce noise and vibration in the braking process.Firstly，this paper introduces the structure of disc brakes, disc brake noiseclassification, and the analysis of disc brake on domestic process noise controlmethods，While the thesis content, and the technology used to do a routeoverview。Secondly, the dynamics analysis had done with theory of frictionbraking and the analysis of brake’s modal the extract of resonant modes weredone by the use of modal analysis theory and finite element analysis softwareABAQUS method combining. On this basis, with the use of finite elementanalysis theory, the braking process is simulated. And then we do some researchon brake noise control by the use of methods and strategies about passive noisecontrol and active noise control. On the passive control, we controlling the brakeparts resonance by comparing the material of brake disk and make improvementon brake pads structural. On the active control we control Brake surfaceself-excited vibration and amplitude jitter by PID and AFC （Active Force control）control theory, combined with MATLAB/Simulink simulation platform. Finally,the acoustic analysis software Virtual Lab for noise control was compared.The results showed that: the brake, the brake negative damping sheet appearsto stimulate the self-excited vibration of the brake system; the brake disc, brakelinings resonance, and the amplitude of the brake disc surface point beating areinduced causes brake noise. For these aggravating factors, reducing brake disc isconducive to reducing the Young’s modulus of the natural frequency of the brakedisc, so as to avoid resonance noise generation; friction sheet-like structure openfor reducing noise due to resonance with a certain effect. When α≤0.022, thebrake disc tend towards stable within2s amplitude under the PID and AFC jointcontrolling. The brake disc’s vibration amplitude decreases from1×10^-3mto1×10^-6m. After controlling Methods the detent’s maximum sound pressure can be control to82.3dB as a maximum value while under5000Hz. Compared withthe numerical value100dB before optimization, it had lowered17.7dB.The research results of the thesis indicated that the impact of brakingsystem’s noise had reduced under specific controlling condition.The researchmethods and outcomes that the research achieved have some significance for thedesigning of braking system.