The Study Of Vibration Characteristic Of Brake Pad And Silencer Of Vehicle's Disk Brake

The vibrations of the automotive disk brake not only affect its performance, but also produce noise to influence the health of person's mind and body. Based on the following two sides, the principle of reducing vibration and the analysis of harmonic response, the vibration characteristics of the assembly—the brake pad and the silencer are studied, the factors which affect vibration are explored, and vibration analyzing models of brake pad and silencer are established. Through the study and analysis, the ways to improve the effect of the silencer's vibration reduction and the optimization blue print are brought forward. The results can improve the whole performance of disk brake.The finite element analysis parametric models are established about the brake pad and the silencer, based on the structural features of two bodies by the FEA software ANSYS. By analyzing the models' modal frequency, the thesis calculated the syntonous frequency which occur vibration. The thesis analyses the modal of silencer with three layers structure and two layers structure respectively, and the structures of which consist of sheet steel and glued rubber. The results of silencer's modal analysis show that, when the thickness of rubber layer increased (two surface rubber layer thickness equal, in the center the sheet steel thickness is constant), the modal frequency of all sets will decrease responsibly. The silencer of two layers structure also has same changes. When the thickness of rubber layer is equal, and the thickness of sheet steel is equal too, the modal frequency of three layers is smaller than the two layers'.This paper analyzed the harmonic response of disk brake pad, and the assembly body of disk pad and silencer, then contrasts all the results in different limited conditions based on ANSYS. It shows that when the load is increased, the vibration amplitude will be strengthened. The silencer decreases the vibration between the brake pad and the piston much better than the vibration between the brake pad and the brake disk. The value of damping plays a vital role in decreasing vibration. When the damping value is constant, it is no good to decrease vibration to change the thickness of rubber layer in small range.By calculation and analysis, It founds that make the damping material directly recombination on the surface of brake pad, or remove the silencer, the brake pad itself adopt high damping alloy, can attain better effect to reduce vibration.This paper optimized the brake pad with sub-problem method based on its harmonic response vibration data, used the thickness parameter 'h' and damping value as design variables, limited stress as state variable, and the volume of brake pad as object function. The optimization result shows the value of thickness and the minimum volume's value under the limits. This method is useful to direct the design of brake pad perfectly.