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在分析货物列车踏面制动方式下车轮踏面热振裂纹和车轮热疲劳裂纹产生机理的基础上,以国内碾钢车轮材料为对象进行踏面制动温度场试验,重点研究制动过程中摩擦热源向转动车轮踏面表面传热的关系,模拟车轮旋转周期内闸瓦摩擦生热和对流换热交替变化的规律,建立车轮制动过程瞬态温度场三维有限元模型,改进以整体输入热流和对流换热的简化模式为基础的传统理论的热应力计算方法。通过在摩擦制动动力试验台进行的制动试验,证明计算模型从宏观和细节方面比较完整地反映了车轮踏面制动热温度场的实际工况。为确定车轮踏面制动极限和作用方式、列车制动距离等技术规范提供计算依据。
Based on the analysis of the thermal shock cracks of the wheel tread and the mechanism of the thermal fatigue cracks of the wheel under the tread brake mode of the freight train, the temperature field test of the tread of the wheel steel is carried out. The research focuses on the frictional heat source The relationship between heat transfer and surface heat transfer of wheel tread is simulated, the law of frictional heat generation and convective heat transfer alternation between wheel rotation cycles is simulated, and a three-dimensional finite element model of transient temperature field during wheel braking process is established. Thermal simplified mode based on the traditional theory of thermal stress calculation method. According to the braking test carried out on friction brake test bed, it is proved that the calculation model reflects the actual conditions of the wheel thermal braking temperature field in a more complete and macroscopical and detail way. To determine the wheel tread braking limit and mode of action, train braking distance and other technical specifications provide the basis for calculation.