12号合金钢组合辙叉单开道岔疲劳裂纹萌生寿命预测

基于有限元分析软件建立12号合金钢组合辙叉单开道岔静、动力学分析模型;基于列车直、侧向过岔的动力仿真结果,确定岔区钢轨疲劳敏感区域,并提取敏感区域疲劳荷载谱;采用静力分析模型研究单位荷载下各敏感区域钢轨内部应力分布情况;基于Miner线性累积法则对岔区钢轨疲劳裂纹萌生寿命进行预测;研究列车轴重、速度对钢轨裂纹萌生寿命的影响;给出不同轴重、不同速度列车通过时岔区钢轨疲劳敏感区域裂纹萌生寿命的预测公式.结果表明:道岔不同敏感区域钢轨的疲劳裂纹萌生寿命相差很大,列车轴重及侧向通过速度对钢轨的疲劳裂纹萌生寿命有很大影响,疲劳裂纹萌生寿命随列车轴重的增加而大幅降低,随列车侧向通过速度的增加也有所降低.

Prediction of rail fatigue crack initiation life of No.12 alloy steel single turnout with combined frog

The static and dynamic analysis models of No.12 alloy steel single turnout with combined frog are established based on finite element analysis software.The fatigue sensitive are-as of turnout rail are located by the dynamic simulation results of the dynamic model when the train is passing through the turnout in a straight or branch line,the load spectrums of each sensi-tive area are extracted for fatigue analysis.The internal stress of rails in each sensitive area under unit load are researched by the static model.The fatigue crack initiation lives of rails in sensitive areas are predicted based on Miner linear cumulative rule.The effects of axle-weight and vehicle speed on the fatigue crack initiation lives of rails are studied.A prediction formula of fatigue crack initiation lives of rails in sensitive areas under different axle loads and vehicle speeds is given.The results show that the fatigue crack initiation lives of rails in different sensitive areas of turnout va-ries greatly,and axle-weight and vehicle speed when the train is passing through the turnout in the branch line have great effects on the fatigue crack initiation lives of rails.The fatigue crack in itiation life decreases significantly with the increase of axle-weight,and it also decreases with the vehicle speed when the train is passing through the turnout in the branch line.