高速车辆运行过程中轮轨接触点的测试研究

Research on Measuring Rail-wheel Contact Points During Operation of High-speed Rolling Stocks

轮轨接触点对深化分析轮对运行动态行为、安全性、轮轨接触状态及作用力等起着关键的作用。基于传统车轮辐板应力测量车轮垂向力与横向力方法,考虑车轮磨耗影响,提出一种提高识别轮轨接触点准确度的改进测试方法。通过FEM程序ANSYS软件分析沿车轮踏面不同位置分别作用垂向、横向和纵向力时,车轮辐板表面的应力分布状态。由计算结果可知,沿辐板孔横向表面的径向应力分布随作用载荷位置(接触点)呈现特定的变化规律,为测试轮轨接触点位置提供了可行性。研究表明,在车轮辐板特定区域存在着对横向力和纵向力不敏感的应力区域,可消除由横向力和纵向力引起的干扰影响。根据计算和试验结果,找出车轮上应变片识别精度最佳的布置位置、方向和测试组桥方式,针对在线测试,完善测量桥路的可靠性和抗干扰性,使测试精度更高,接触点位置的确定更准确。分析因车轮踏面磨耗与镟修导致对车轮辐板表面应力分布产生影响的问题,推导出测试修正矩阵,扩展测量识别接触点的适用范围。完成测试轮对的研制,进行线路测试,获取了多种运行条件下接触点的测试结果。

Wheel-rail contact points play an important role in deepening analysis of wheelset running dynamic behavior, safety, wheel-rail contact state and force. An improved approach for measuring wheel rail contact points was put forward based on the traditional method of measuring wheel-rail forces by means of wheel web stress as well as the influence of wheel tread wear. The stress distributions on wheel web surface was analyzed by using FEM program ANSYS when vertical, lateral and longitudinal forces were applied at different positions along wheel tread respectively. The calculation results show that radial stress distributions along the transverse surface of the web hole present a specific law of change via the load positions, i.e., contact points, which provides a possibility for measuring wheel-rail contact points. The studies show that there exist stress regions insensitive to the lateral and longitudinal forces in the specific areas of wheel web, which can eliminate interference effects caused by lateral and longitudinal forces. According to the calculation and test results, the measuring approach is modified for on-track test, and the best arrangements and bridges of strain gauges are developed on the wheel. The reliability and anti-interference of measuring circuit are improved with higher measuring accuracy. The influence of wheel tread wear and turning repair on the stress distributions on wheel web surface was analyzed, and a modified test matrix was given. This improved its measurement precision and scope of application about on-line test. Finally, the development of test wheelset was done, and field operating measurement was completed to obtain and collect the data of contact points under operational conditions.