考虑磨耗的钢轨疲劳裂纹萌生寿命预测仿真

Simulation on Rail Head Crack Initiation Life Prediction Considering Rail Wear

将基于Archard磨耗理论的钢轨型面磨耗模型和基于临界平面法的钢轨疲劳裂纹萌生寿命预测模型通过分段迭代和疲劳累积的方法统一起来,提出考虑磨耗的裂纹萌生寿命预测方法,分析了U75V热处理钢轨在磨耗下的裂纹萌生特征。分析结果表明：考虑磨耗的裂纹萌生寿命预测结果更接近现场观测结果,裂纹萌生位置较不考虑磨耗时更靠近轨顶中心;曲线外轨的裂纹萌生寿命约为4.5×10^7 kN,对应车轮通过次数约为2.17×10^5次,在轮轨摩擦系数为0.3时,裂纹萌生在距离钢轨表面2.42mm以下的位置;在钢轨上道至车轮通过次数约为1.22×10^5次、对应通过总重约为2.24×10^7 kN时,轮轨关系较稳定,磨耗和疲劳裂纹萌生发展缓慢。

The method of rail head crack(HC)initiation life prediction considering rail wear was presented by combining the rail profile wear model based on Archard theory with rail HC initiation life prediction model based on the critical plane theory using the worn rail profile iteration according to the wear amount and cumulative fatigue damage.The HC initiation characteristics of U75Vheat-treated rail considering the wear were analyzed.The results showed that the results of HC initiation life prediction considering the rail wear were closer to the field observation results.The HC initiation position was closer to the center of the rail top than the HC initiation position without considering the rail wear.The HC initiation life of the high rail was about 4.5×10~7kN(wheel cycle of about 2.17×10~5)of the traffic gross tonnage.With the wheel/rail friction coefficient of 0.3,the position of HC initiation was at 2.42 mm below the rail surface.The steady wheel/rail interaction with slow growth of wear and HC initiation can be realized at the early stage after the rail laying until the traffic gross tonnage was about 2.24×10~7 kN(wheel cycle of about 1.22×10~5).