Yucheng Liu

Brake noise is one of the principal components of vehicle noise and is also one of the most critical measures of vehicle quality. During the braking process, the occurrence of brake noise has a significant relationship with the working conditions of the brake system. In the present study, dynamometer test data and the finite element method (FEM) were used to analyze the direct and indirect effects of variations in the working parameters on the brake noise, and a brake noise reduction method was developed. With this method, Monte Carlo sampling was used to consider variations in the parameters of the brake lining during the braking procedure, and the particle swarm optimization method was used to calculate the optimal parameter combination for the brake lining. A dynamometer test was carried out to validate the effect of optimization on brake noise mitigation.

Brake noise, a principal component of vehicle noise, is among the most critical measures of vehicle quality. The perceived quality of cars can be improved by reducing brake noise; therefore, vehicle manufacturers are extensively investigating the influencing factors, generating mechanism, and solutions of brake noise. Compressive strain is one of the most influential performance parameters of a brake pad and can be adjusted by regulating the material elastic modulus and by modifying the shape of the brake lining. In this study, the compressive strain of a brake pad was adjusted through four methods, and the noise characteristics of brake pads with different elastic modulus, section outlines, lining widths, and chamfers were studied through finite element analysis and the complex-eigenvalue method. The effects of compressive strain of a brake pad on brake noise were examined, and an optimized brake-pad scheme was developed. A dynamometer test conducted to validate the effectiveness of the optimized scheme confirmed a clear alleviation in brake noise.

A 7‐degree‐of‐freedom (DOF) vibration model of a fixed‐caliper disc brake system was developed herein based on the Stribeck effect. Furthermore, a dynamometer brake test was conducted to determine the characteristic system parameters of the 7‐DOF vibration model. This model was developed to study the effects of braking conditions, such as disc rotational speed and brake pressure on brake noise. The complex eigenvalues of the system were also calculated to analyze the brake model stability under different braking conditions. The acceleration time history diagrams and phase plots were obtained by solving the equations of the system. The numerical calculation results showed that the brake noise increased with an increasing braking force and a decreasing breaking speed. These numerical findings were verified by the results of the dynamometer tests.