Parameter optimization for high-speed train brake disc noise reduction based on orthogonal test method

Abstract With the continuous increase in train speed, braking noise has emerged as a critical issue. To investigate and mitigate this problem, this study applies complex modal analysis based on modal coupling theory to evaluate the noise response of brake discs under specific operating conditions. The influence of key parameters, namely friction coefficient and the elastic moduli of both the brake disc and pad, on noise generation is examined. Results indicate that the friction coefficient is positively correlated with braking noise tendency, while the elastic modulus of the brake disc has a negligible effect. Using orthogonal experimental design combined with range and variance analysis, the sensitivity of various design parameters to braking noise is assessed. The parameters, in descending order of influence, are friction coefficient, brake disc thickness, brake pad elastic modulus, friction block chamfer, brake disc elastic modulus, and brake pad thickness. Among these, friction coefficient, brake disc thickness, and brake pad elastic modulus significantly affect noise generation, while the chamfer of the friction block also shows a notable influence. Subsequently, response surface methodology is employed to optimize the friction block chamfer, brake disc thickness, and brake pad thickness. After-optimization complex modal analysis reveals a substantial reduction in braking noise response, with the system instability tendency coefficient decreasing by 50.12%, demonstrating the effectiveness of the proposed optimization approach.