Abstract
Rail is an important component of railway,it guides the vehicle forward,carries and loads various loads from the wheels and plays an important role in the railway.With the rapid development of domestic railway,the demand for railway transportation continues to increase, the working conditions of rail become more and more severe,the fatigue damage of the rail becomes more and more serious,thereby endangering the stability and safety of the train. Therefore,the maintenance and repair of rails become more and more important.Rail grinding is an important way of rail maintenance operation,which can effectively eliminate and restrain rail surface damage,extend replacement cycle of the rail and bring huge economic benefits. Through decades of application and development,rail grinding has become a routine maintenance and repair technology for railway around the world.
Rail grinding is the process of removing rail material and optimizing rail profile by grinding equipment.In order to analyze the influence of rail profile on the wheel-rail contact relationship of railway vehicle,the dynamic simulation model of HX D2locomotive,25K passenger car and C70freight car are established based on different structural characteristics by multi-body dynamics software SIMPACK.According to the rail profile data measured from a domestic railway line before and after rail grinding,the paper calculates the distribution of the wheel-rail contact points of different vehicles by the numerical calculation program,analyzes the reason of rail damage and the improvement of the surface defects and light distribution after rail profile variation.
In order to analyze the impact of rail profile on the dynamic performance of railway vehicle, the stability,stationary,curve through performance and other dynamic performance of different vehicles before and after rail profile variation are calculated and analyzed by changing the rail profile in the model.The simulation results show:rail profile optimizing can increase the vehicle critical velocity and improve the stability of the hunting movement;rail profile optimizing can reduce the wheel-rail lateral force,axle lateral force,derailment coefficient, lateral acceleration and lateral stability of locomotive,passenger car and freight car while it has less influence on wheel-rail vertical force,wheel load reduction rate,overturning coefficient, vertical acceleration and vertical stability indicator;the abrasion power of vehicle after rail profile optimizing is reduced to a certain extent,which is helpful to reduce the wheel and rail wear and extend the rail replacement cycle.
In order to improve the curve performance of heavy haul freight car on60N rail,several rail profiles between60N rail and60rail are designed to optimize the rail in this paper.The results of dynamic calculation show that the closer rail optimized profile to60rail,the better curve passing performance;the closer rail optimized profile to60N rail,the lower wheel rail abrasion.
A rail profile that can satisfy the curve passing performance and minimize the wheel and rail wear is determined through analytic hierarchy procsse,and the program of the rail profile optimization design is provided to the line engineering department.
Keywords:rail profile;wheel-rail contact relationship;vehicle dynamics performance;rail profile optimization
目录
第1章绪论 (1)
1.1研究背景及意义 (1)
1.2钢轨打磨技术研究现状 (3)
1.2.1国外研究现状 (3)
1.2.2国内研究现状 (6)
1.2.3钢轨廓形研究现状 (7)
1.3论文主要研究内容 (8)
第2章机车车辆动力学模型的建立 (10)
2.1多体动力学软件SIMPACK简介 (10)
2.2机车车辆动力学模型的建立 (10)
2.2.1模型的简化及非线性因素处理 (10)
2.2.2机车动力学模型 (12)
2.2.3客车动力学模型 (14)
2.2.4货车动力学模型 (16)
2.2.5轨道不平顺 (18)
2.3本章小结 (21)
第3章钢轨廓形对轮轨接触关系的影响 (22)
3.1轮轨型面的采集与分析 (22)
3.2轮轨接触几何关系计算原理 (24)
3.2.1轮轨廓形的坐标变换 (24)
3.2.2轮轨接触几何关系计算 (26)
3.3典型区段轮轨接触关系分析 (27)
3.3.1直线轮轨接触关系分析 (28)
3.3.2小半径曲线轮轨接触关系分析 (32)
3.3.3大半径曲线轮轨接触关系分析 (35)
3.4本章小结 (38)
第4章钢轨廓形对机车车辆动力学性能的影响 (39)
4.1客车、货车和机车动力学性能评价指标 (39)
4.1.1运行平稳性 (39)
4.1.2运行稳定性 (41)
4.1.3车辆运行安全性 (42)
4.1.4通过曲线时的磨耗性能 (45)
4.2钢轨廓形对机车车辆临界速度的影响 (45)
4.3钢轨廓形对机车车辆运行平稳性的影响 (47)
4.4钢轨廓形对机车车辆直线运行性能的影响 (49)
4.4.1钢轨廓形对直线轮轨作用力的影响 (50)
4.4.2钢轨廓形对直线轮重减载率的影响 (52)
4.4.3钢轨廓形对直线脱轨系数的影响 (52)
4.5钢轨廓形对机车车辆曲线运行性能的影响 (54)
4.5.1钢轨廓形对曲线轮轨作用力的影响 (56)
4.5.2钢轨廓形对曲线轮重减载率的影响 (58)
4.5.3钢轨廓形对曲线脱轨系数的影响 (58)
4.5.4钢轨廓形对线路横向稳定性系数的影响 (60)
4.5.5钢轨廓形对倾覆系数的影响 (60)
4.5.6钢轨廓形对磨耗功率的影响 (61)
4.5.7钢轨廓形对轮轨蠕滑的影响 (62)
4.5.8钢轨廓形对轮轨接触应力的影响 (64)
4.6本章小结 (65)
第5章小半径曲线钢轨型面优化 (67)
5.160N钢轨简介 (67)
5.2钢轨廓形优化 (68)
5.3钢轨廓形优化方案综合评价 (72)
5.4本章小结 (78)
结论与展望 (79)
致谢 (81)
参考文献 (82)
攻读硕士学位期间发表的论文及参与科研项目 (87)
第1章绪论
1.1研究背景及意义
铁路是我国重要的基础设施、国民经济大动脉以及大众化的交通工具，在现代物流体系中发挥着重要的作用。我国铁路运输行业正在持续高速发展，运营里程在2016年底已达到12.4万km，根据中长期铁路规划(2016-2030)，2020年我国铁路网规模将会发展到15万km，其中包括高速铁路3万km，覆盖80%以上大城市。随着铁路事业高速发展，我国旅客运输和货物运输的需求持续增长，列车行驶密度持续增加，钢轨的工作环境愈加恶劣，钢轨质量下降，服役周期缩短，钢轨问题变得日益严重。钢轨在长期负荷状态下会出现各种疲劳伤损，例如钢轨侧磨、擦伤、波浪形磨损、轨头压溃、肥边、裂纹和钢轨断裂等，如图1-1所示，这些钢轨缺陷威胁列车行车安全，因此钢轨需要定期检测和维护。钢轨维护方式主要分为钢轨更换与重铺、钢轨润滑和钢轨打磨，其中钢轨打磨维护成本比换轨低，适合钢轨损伤程度在一定范围内的线路养护，能有效清除并抑制钢轨表面的多种病害，延长钢轨更换周期，已被广泛应用于全球多个国家铁路常规线路养护维修工作中[1]。
(a)钢轨侧磨(b)钢轨擦伤
(c)钢轨波磨(d)轨面剥离
图1-1几种典型的钢轨损伤
钢轨打磨是运用打磨机械或打磨列车对钢轨进行材料去除并改善廓形的过程，主要依靠打磨设备上的砂轮旋转带动磨粒去除钢轨表面材料，砂轮与钢轨间可以调节不同角度从而实现对钢轨轨头各个部位的磨削，钢轨打磨原理及示意图如图1-2、1-3所示。图1-4为某钢轨打磨作业前后钢轨表面状况对比，可以看出，钢轨在打磨前轨顶及轨距角处