基于临界平面法的钢轨裂纹萌生寿命预测模型研究

A Research on Rail Crack Initiation Life Prediction Models Based on Critical Plane Method

临界平面法是常用的钢轨裂纹萌生寿命预测方法,诸多文献分别基于此研究了相关的预测模型,但计算出的钢轨裂纹萌生寿命时间比现场观测到的裂纹萌生寿命稍短。通过对预测模型进行理论分析,结果认为,蠕滑力在裂纹萌生预测模型中起十分重要的作用,尤其是纵向蠕滑力与自旋蠕滑力。采用全蠕滑状态是致使预测结果比实际观测结果要短的重要原因之一。此外,摩擦热应力产生的残余应力为拉应力,不平顺导致接触应力的改变,钢轨材质与夹杂物的影响,以及裂纹萌生阶段的选取准则,磨耗的影响等,都应在钢轨滚动接触疲劳裂纹萌生寿命预测中有合理考虑。

Many relevant prediction models are studied based on the critical plane method,which is commonly used in prediction of rail crack initiation.But the crack initiation life span of the prediction result is shorter than that of site observation.The result of theoretical analysis shows that creep force,especially the longitudinal creep force and spin creep forces,plays an important role in crack initiation prediction models.Full sliding state is an important reason why the predicted result is shorter than the result of actual observations.In additiont,he thermal stress generated by friction includes tensile residual stressc,hange of contact stress caused by irregulari-tyt,he impact of the rail materials and inclusiont,he selection criteria in crack initiation stagea,nd the impact of the wear,which should be considered in RCF cracks initiation life prediction.