非椭圆接触下地铁小半径曲线外轨全寿命侧磨发展规律

对Archard材料磨耗模型进行了改进,使其更加适合考虑非椭圆接触的钢轨侧磨仿真;将地铁列车荷载谱按客流量分为3类,基于地铁常用A,B型车辆标准模型及小半径曲线参数,建立不同载重条件下的车—轨多体动力学模型,考虑轮轨非椭圆接触计算切向蠕滑功并按权重进行累积,预测外轨侧磨随运营时间的发展规律,并与长期现场跟踪测试结果进行对比验证。结果表明:地铁小半径曲线外轨侧磨的发展可分为3个阶段,阶段Ⅰ磨耗从轨距角部分开始产生并向轨顶与轨侧扩展,尚未达到侧磨位置处;阶段Ⅱ开始出现侧磨并呈线性发展,A,B型车产生的月侧磨速率分别为0.53和0.46mm;侧磨达到9mm左右进入阶段Ⅲ,侧磨速率明显提高,磨耗位置稳定;预测的侧磨发展规律和钢轨型面演变与现场跟踪测试结果十分吻合,表明利用本方法能够以较小的成本对外轨全寿命阶段侧磨进行分析研究。

Development Law of Life Cycle Side Wear on Outer Rail of Metro with Small Radius Curve under Non-Elliptical Contact

The Archard wear model was improved to make it more suitable for the simulation of rail side wear considering non elliptical contact.The load spectrums of metro trains were classified into three categories according to passenger flow.The vehicle-track multi-body dynamics models under different load conditions were established respectively based on the parameters of small radius curve and the standard models of type-A and type-B vehicles commonly used in metro.Considering the non elliptical contact between wheel and rail,the tangential creep work was calculated and accumulated according to weights.The development law of the side wear on outer rail with the service time was predicted and compared with long term tracking test results.Results show that the development of the side wear on the small radius curve of metro can be divided into three phases.In phase Ⅰ,the wear starts from the gauge corner and expands rapidly to the top and side of the rail,and has not yet reached the side wear position.In phase Ⅱ,the side wear appears and starts to develop linearly.The monthly side wear rates of A-type and B-type vehicles are 0.53 and 0.46 mm respectively.When the side wear reaches about 9 mm,it enters phase Ⅲ.The side wear rate is significantly increased,and the wear position is stable.The predicted development law of side wear and the evolution of rail profile agree well with field tracking test results,which indicates that this method can be used to analyze the side wear of the outer rail in the life cycle stage at a lower cost.