Analysis On Generation Mechanism And Transfer Path Of Vibration And Noise Of Automotive Disc Brake

With the improvement of people’s requirement on automotive safety and comfort, the vibration and noise generated by a brake are paid more and more attention. In the process of braking, the vibration generated by a brake will make the body shake, driver tired and cause serious traffic accident. The noise generated by a brake will cause noise pollution to the environment and make the driver and the pedestrians nervous and uneasy. It is very meaningful to study the generation mechanism and transfer path of vibration and noise of automotive brakes, and it can provide theoretical basis for reducing the vibration and noise.First, study the generation mechanism of vibration and noise from the view of resonance of a brake. The first step is building a finite element model of an automotive disc brake. Afterwards, analyze the modal of the brake disc and friction plate using the ANASYS Workbench software, and observe their modal frequencies and shapes. Through the contrast of the modal frequencies and the excitation frequency endured by the brake, the brake disc may generate resonance phenomenon but the friction plate cannot generate resonance phenomena. In addition, change the thickness of the brake disc, the number of radiating rib plate and the modulus of elasticity of the brake disc, and analyze the influence of these parameters on the modal of the brake disc. It concludes that the influence of modulus of elasticity is the most serious one. Finally, the method of reducing vibration and noise is put forward.Second, the braking process of a disc brake is a classical thermal-structure coupling process, and the thermal deformation is caused by frictional heat. Study the generation mechanism of vibration and noise from the view of thermal deformation. Analyze the pure structure, temperature field and thermal- structure coupling of the brake disc, and have these results contracted. It confirms that the braking process is a highly coupling process between temperature field and stress field. The frictional heat generated in the braking process has a great effect on the stress of the brake disc, and the thermal stress is the main stress. The hot judder caused by thermal deformation is another reason of the vibration and noise of disc brake.In the end, use the ADAMS/view software to establish an automotive front suspension system model, and make vibration simulation analysis on the model through the ADAMS/Vibration modular. The vibration of the disc brake is simulated by a vibration excitation defined on the rotating center of the brake disc. Afterwards, the frequency response function of some nodes on the suspension system can be acquired. By analyzing these frequency response functions, the most severe vibration of node is found, and it is located on the drag link. The next step is to analyze the effect of vibration on the driver.