In this research, the bolts fracture problem of brake disc under a section downhill of the Lanzhou-Wulumuqi railway (LW) line has been studied via experimental and fatigue analysis. The physical and chemical properties of the bolts were examined to analyze the fracture causes. In addition, the LW line condition was investigated and fitted to obtain the altitude-velocity histories. The finite element model of the brake disc was established with the thermo-mechanical coupling method to obtain the temperature and stress variation. Results revealed that the material defect was inexistence at the thread root, and the bolt performances meet relevant standards. Due to special geographical conditions in LW line, the train have to brake continually. The bolt fracture of the brake disc is caused mainly by high temperature during the continuous braking.

本研究通过试验和疲劳分析研究了兰乌乌鲁木齐铁路下坡段制动盘螺栓断裂问题。检查了螺栓的物理和化学性质以分析断裂原因。此外，对LW线条件进行了研究并进行拟合，以获取高度-速度历史记录。利用热力耦合方法建立了制动盘的有限元模型，以求得温度和应力的变化。结果表明，螺纹根部不存在材料缺陷，螺栓性能符合相关标准。由于LW线的特殊地理条件，列车必须不断制动。制动盘的螺栓断裂主要由连续制动过程中的高温引起。