Influence of disc brake on wheel polygonal wear of high-speed train

Based on the viewpoint of friction self-excited vibration, the formation mechanism of wheel polygonal wear in high-speed train and related influence factors are studied in this study. Firstly, a field investigation of the Chengdu-Chongqing high-speed railway is conducted. The wheel polygon characteristics of the section is mastered, and the vibration frequencies excited by high-order OOR is obtained. A finite element model considering the brake system and the wheel-rail system is proposed. The unstable vibration frequency distribution and the system stability are studied by complex eigenvalue analysis. Results show that when the high-speed train runs at 300 km/h, the unstable vibration of frequency 652.8 Hz is excited. The unstable vibration will cause periodic fluctuation of wheel-rail friction work, leading to 22–23 order polygonal wear of the trailer wheel. The consistency of simulation results and Field research situation proves the correctness of the proposed method. In addition, the influence factors on the wheel polygonal wear are investigated. The pad with a high damping coefficient can effectively inhibit the 22–23order wheel polygonal wear. Increasing the Young's modulus of the pad will cause the self-excited vibration frequency increases, and the system is prone to higher-order wheel polygonal wear. The Poisson's ratio of brake pad has little effect on wheel polygonal. In addition, the brake pad structure also has a great influence on the self-excited vibration of the system. The brake pads with groove surface can decrease the self-excited vibration frequency and reduce the polygon order.