摘要
基于单轮对荷载作用下钢轨滚动接触疲劳裂纹萌生寿命的预测方法,结合疲劳损伤累积理论,提出基于疲劳损伤累积的钢轨裂纹萌生寿命预测方法,确定转向架前、后轮对累积荷载作用下重载铁路曲线内轨裂纹的萌生寿命及其特征;构造权重参数,用以表征前、后轮对在内轨裂纹萌生过程中各自的作用权重。采用SIMPACK仿真软件建立C70型货车、LM型车轮踏面、U75V钢轨构成的车辆—轨道模型,预测不同曲线半径、超高、轨底坡和摩擦系数工况下内轨裂纹的萌生寿命、萌生位置和开裂方向、权重参数,并与现场试验进行对比。结果表明:内轨裂纹的萌生要早于外轨,并发生在距离轨顶约2~3mm的轨头次表面,车轮对内轨的磨耗作用不大;在内轨裂纹的萌生过程中,随着轨道条件的变化,轮对的权重取值范围可以划分为3个区域,分别对应前轮对作用权重绝对大和相对大以及后轮对作用权重相对大3类情况;大多数内轨裂纹的开裂方向分布在一定的范围之内,但有少部分裂纹的开裂方向异常且在扩展过程中容易产生剥离掉块。
Based on rolling contact fatigue crack initiation life prediction method under single rail wheel load and combined with the fatigue damage accumulation theory,the rail crack initiation life prediction method based on fatigue damage accumulation was proposed to determine heavy haul curve rail crack initiation life and its characteristics under the cumulative loads by front and rear wheels of bogie.The weight parameter was configured for characterizing the respective role weight of the front and rear wheel in the inner rail crack initiation process.A vehicle-track model was established by simulation software SIMPACK,which consisting of C70 freight car,LM type wheel tread,U75 Vrail.The model was used to predict rail RFC crack initiation life,initiation position and cracking direction,weight parameters in various tracks which owned different curve radius,superelevations,rail cants and the coefficient of friction conditions.The field test was carried out for comparison.The results show that：cracks in the inner rail are initiated earlier than in the outer rail,and they are located on the sub-surface of approximately 2-3mm from rail head,so they are affected little by wear from wheel rail contact.In the crack initiation process of inner rai,the role weight of wheel in the range can be divided into three regions with the changing of track conditions,which correspond to the absolute majority role weight of front wheel,the relative majority weight of front wheel and the relative majority weight of rear wheel.Most crack initiation angles are within a certain range,but a small part of cracks has the abnormal cracking direction.They will link together when they propagate to a certain extent and the spalling is produced.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2017年第1期29-36,共8页
China Railway Science
基金
国家自然科学基金资助项目(51268014
51578238)
江西省教育厅科研项目(GJJ150508)
关键词
曲线内轨
裂纹萌生
剥离掉块
临界平面
损伤累积
轮对作用权重
重载铁路
Inner rail on curve
Crack initiation
Spalling
Critical plane
Damage accumulation
Wheel action weight
Heavy haul railway
