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以现场实测轮轨力为样本,利用参数假设检验方法,确定轮轨力幅值和频率特征,进而根据轮轨力分布特征编制荷载谱。建立轨道结构的多跨连续梁模型,分析群载作用下钢轨受力情况,确定最大弯曲应力所在位置;利用子模型技术,取最大弯曲应力所处的一跨钢轨为研究对象,建立子模型,分析不同幅值下轮轨接触斑内局部应力情况。根据临界平面法思想,建立随机轮轨力作用下钢轨滚动接触疲劳裂纹萌生寿命预测模型。结合具体实例分析表明:在一定速度范围内,轮轨力符合正态分布;根据随机轮轨力作用下钢轨滚动接触疲劳裂纹萌生寿命预测模型,预测U75V钢轨通过约560万吨总重时轨面萌生裂纹,与现场观察结果吻合。
Taking the measured wheel-rail force as a sample, the method of parameter hypothesis testing was used to determine the amplitude and frequency characteristics of the wheel-rail force, and then the load spectrum was compiled according to the wheel-rail force distribution characteristics. The multi-span continuous beam model with orbital structure was established to analyze the stress condition of the rail under group load and to determine the location of the maximum bending stress. By using the sub-model technique, taking the one-span rail with the maximum bending stress as the research object, The analysis of the local stress in the wheel-rail contact patch under different amplitudes. According to the idea of critical plane method, a prediction model of rolling contact fatigue crack initiation life under random wheel-rail forces is established. The analysis of concrete example shows that the wheel-rail force is in normal distribution within a certain speed range. According to the predicting model of rolling contact fatigue crack initiation life under random wheel-rail force, the U75V rail is predicted to pass through about 5.6 million tons of total weight hour-track surface Initiation of cracks, consistent with the observations on the spot.