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1、Methods for Analysis of Wheel/Rail Interaction and Design of Wheel and Rail Profiles轮轨相互作用的分析方法和轮轨外形的设计,1,轮轨相互作用的分析方法和轮轨外形的设计,Agenda目录,Tools for the Measurement of Wheel/Rail interaction 用于测量轮轨间相互作用的工具 Methods to Analyze Wheel/Rail Interaction 轮轨相互作用的分析方法 Process for the Design of Wheel and Rail Pro
2、files 车轮和钢轨外形的设计过程,2,轮轨相互作用的分析方法和轮轨外形的设计,Simple Diagnostics简单诊断,Visual Observation of RCF on Wheels 车轮上RCF（滚动接触疲劳）的目测,Visuals are more effective with a rating scale and job aid目测是一种更有效的评定量表和工作辅助,2,3,4,5,“As-ground” Rail Templates vs. Standards“打磨”钢轨模板与标准,Templates designed for 0.4 mm gauge corner re
3、lief 轨距角退让0.4mm的模板,Rails ground to fit template within 0.25mm 与模板误差小于0.25mm的打磨后的钢轨,Wheel Gauges and Examples of Standards轮对内侧距和标准的例子,22 mm min. 轮缘厚度最小22mm,38 mm max. 轮缘高度最大38mm,3 mm max. 中间磨耗最大3mm,Manual Wheel or Rail Profile Measurement with MiniProf手持式MiniProf的车轮或钢轨外形的测量,Strain Gauging of Rails to
4、 Measure Lateral and Vertical Forces by Axle在钢轨上用应变仪测量由车轴产生的垂向力和水平力,Laser-based wheel and rail profile measurement systems develop accurate profile and wear measures基于激光的车轮和钢轨外形测量系统可以精准测量外形和磨损,Automated Rail Assessment Tools自动化钢轨评估工具,Use of Tribometer to Assess Rail Friction Levels使用摩擦试验机去评估钢轨黏滑程度,1
5、1,轮轨相互作用的分析方法和轮轨外形的设计,Agenda目录,Tools for the Measurement of Wheel/Rail interaction 轮轨相互的作用的监测工具 Methods to Analyze Wheel/Rail Interaction 轮轨相互作用的分析方法 Process for the Design of Wheel and Rail Profiles 车轮和钢轨外形的设计过程,12,轮轨相互作用的分析方法和轮轨外形的设计,Hertzian Contact赫兹接触,Hertzian Contact (1882) describes the press
6、ures, stresses and deformations that occur when curved elastic bodies are brought into contact. 赫兹接触（1882）描述了当弯曲弹性体接触时发生的压力，应力和变形。 “Contact Patches” tend to be elliptical “接触斑”往往是椭圆形 This yields parabolic contact pressures 这就产生抛物线型接触压力 Under the rail surface, this yields a tri-axial stress state, le
7、ss so as contact patch nears the edge of rail and wheel. 在轨面上会产生一个三轴向应力状态，较小的接触斑会靠近钢轨和车轮的边缘,13,轮轨相互作用的分析方法和轮轨外形的设计,Hertzian Contact赫兹接触,The contact stresses between the average wheel and the rail profile designs should not exceed: 磨耗车轮与设计的钢轨外形之间接触应力不应超过 o 1500 MPa for soft (280 HB) rail 对于软钢轨（280HB）
8、为1500MPa o 1700 MPa for intermediate (320 HB) rail 对于中等硬度钢轨（320HB）为1700MPa o 2000 MPa for premium (380 HB) rail 对于优质钢轨（380HB）为2000MPa,14,轮轨相互作用的分析方法和轮轨外形的设计,Creep Forces蠕滑力,注解 没有所谓的“静态”和“滚动”摩擦,蠕滑的概念 结合刚体力学和弹性力学 在滚动的条件下，牵引轮与 钢轨接触之间会产生不同的应变 滑动发生在接触斑的部分区域,15,轮轨相互作用的分析方法和轮轨外形的设计,Rail pummelling software
9、 calculates where wheels will contact rail and at what contact stress level轮轨接触软件计算车轮与钢轨的接触和接触应力水平,22个转向架（导向和跟随车轴）在图示不同的位置匹配钢轨时，可以显示钢轨损伤的位置和程度,16,轮轨相互作用的分析方法和轮轨外形的设计,Pummelling is the Cross Product of the Contact Stress times the Frequency of the Contact 匹配分析是指接触应力次数和接触频率之间的乘积,17,轮轨相互作用的分析方法和轮轨外形的设计
10、,Contact stress x frequency of contact = surface fatigue potential表面潜在的疲劳=接触应力*接触频率,RCF Development: Shakedown滚动接触疲劳的发展：安定性,Reduced Stress(e.g. wheel/rail profiles) 减少应力 (例如车轮/钢轨外形),Increased Matl Strength 提高材料的硬度,Reduced Traction Coefficient(e.g. reduced friction) 减少切向力系数 (例如：减少摩擦力),0,0,1,0,2,0,3,0
11、,4,0,5,0,6,1,2,3,4,5,6,7,traction coefficient T/N 切向力系数T/N,load factor 负载系数,plastic Shakedown 塑形安定,elastic shakedown 弹性安定,Elastic 弹性,Ratchetting 渐变,Subsurface 亚表面,Surface 表面,p0/ke,19,轮轨相互作用的分析方法和轮轨外形的设计,Contact Stress Analysis vs. Shakedown Limit Diagram estimates rolling contact fatigue damage接触应力分
12、析和安定性极限图，可以预估出滚动接触疲劳损伤,轮轨相互作用的分析方法和轮轨外形的设计,Wheel/Rail Conicity Analysis Checks Vehicle Stability轮轨等效锥度的分析，检查车辆的稳定性,轮轨相互作用的分析方法和轮轨外形的设计,Analysis of wheel rolling radius difference vs. lateral wheel set movement车轮滚动圆半径差与轮对横移量之间关系分析,轮轨相互作用的分析方法和轮轨外形的设计,Rolling Radius Difference滚动圆半径差,Not enough (Insuff
13、icient)不足的时候 Poor steering 导向能力不足 Flanging轮缘贴靠 Wear磨耗 Noise噪声 Just enough 刚刚好的时候 Perfect steering完美导向 Free rolling自由滚动 Too much (Excessive) 太多（过度） Mild curves 轻度曲线 High longitudinal forces 大的纵向力 High conicity profiles encourage wheel-hollowing 高的轮缘锥度导致凹形车轮,轮轨相互作用的分析方法和轮轨外形的设计,Agenda目录,Tools for the
14、Measurement of Wheel/Rail interaction 轮轨相互的作用的监测工具 Methods to Analyze Wheel/Rail Interaction 轮轨相互作用的分析方法 Process for the Design of Wheel and Rail Profiles 车轮和钢轨外形的设计过程,24,轮轨相互作用的分析方法和轮轨外形的设计,Process for Wheel and Rail Profile Design轮轨外形的设计过程,1、Collect a sample of worn wheel profiles that approximate
15、ly represents the distribution of worn wheel shapes that operate over the railway or route in question. 收集磨耗车轮外形的样本，以近似代表有问题的路线的磨耗轮形状分布。 2、Collect a sample of worn rail profiles that approximately represents the distribution of curvature on the railway/route in question. 收集磨耗钢轨外形的样本，近似代表了有问题的线路上不同曲线
16、半径的分布。,25,轮轨相互作用的分析方法和轮轨外形的设计,Process for Wheel and Rail Profile Design轮轨外形的设计过程,3、Document the damage seen on the rails. 记录钢轨上的损伤。 4、 Pummel these wheels on the rails (cumulative damage simulations), to establish baseline performance and to verify that any damage seen on the rails shows up in the p
17、ummeling plots (validates the model) 轮轨匹配计算（累计损伤模拟），建立了基线性能，通过钢轨上显示的接触点并验证钢轨上的任何损伤。,26,轮轨相互作用的分析方法和轮轨外形的设计,Process for Wheel and Rail Profile Design轮轨外形的设计过程,5. The rail profiles would be modified to take load away from any location where it is concentrated and causing damage, and redistribute it ov
18、er the rest of the running surface. The results of these modifications need to be checked by pummeling again it is an iterative process. 修改钢轨的外形，使得负载远离那些应力集中和造成损害的任何位置，并将负载重新分配在钢轨表面的其余部分。这些修改后的外形，需要再次通过匹配检查.这是一个迭代过程。,27,轮轨相互作用的分析方法和轮轨外形的设计,Process for Wheel and Rail Profile Design轮轨外形的设计过程,6. For a
19、mild curve high rail (wheels shifted towards high rail but most wheels not flanging), alter the gauge corner and crown to raise the shoulder this encourages steering. It is important to manage contact stresses, so the design should produce conformal contact. 对于中等半径曲线的外轨（轮子移向外轨但是大多数的轮子不会发生轮缘贴靠），改变轨距角
20、和轨冠来提高轨肩这是促进导向。这时应重点关注接触应力，因此设计会趋于共型接触。,28,轮轨相互作用的分析方法和轮轨外形的设计,Process for Wheel and Rail Profile Design轮轨外形的设计过程,7. For a sharp curve high rail (wheels flanging), we provide relief at the upper gauge corner (and possibly shoulder) to produce a two-point conformal contact. If there was RCF at these
21、locations because contact stresses or surface tractions were high, relieving them will reduce the stresses. 对于一个小半径曲线外轨（轮缘接触），我们避免上部的轨距角（轨肩）产生两点的共形接触。如果这些位置已有滚动接触疲劳，因为接触应力和表面切向力很高，磨削轨距角将减少压力。 If the relief required to reduce the stresses seems excessive, it may be that there are a significant number
22、 of wheels with an aggressive flange root. If the tractions are too high, TOR-FM may be needed. 如果为减小应力所需的打磨量过大的话，可能使相当多数量的车轮在轮缘根部发生接触，如果切向力很大时，就需要轨顶摩擦控制。,29,轮轨相互作用的分析方法和轮轨外形的设计,Process for Wheel and Rail Profile Design轮轨外形的设计过程,8. If the railway/route has good lubrication, design of the high rail p
23、rofiles should extend to 60 degrees gauge, to ensure that grinding introduces a small amount of artificial wear 如果铁路/线路具有良好的润滑，外轨设计外形应扩展到60度轨距角，以确保打磨时引入人为磨损。,30,轮轨相互作用的分析方法和轮轨外形的设计,Process for Wheel and Rail Profile Design轮轨外形的设计过程,9、For tangent rails (we typically design two profiles), start with a
24、 measured tangent profile that has been observed to perform well (no reports of hunting, no surface damage) and alter the radii on running surface to shift the pummeling distribution slightly to gauge side of centre and modestly to field side of centre. The pummeling distributions for the two design
25、s must overlap somewhat to ensure that a stress riser does not develop on the wheel tread between the contact bands for these two designs. Multiple tangent profiles are used to spread wear across more of the wheel tread, to delay the onset of wheel hollowing. If the railway/route in question has hig
26、h curve density, a single tangent profile may be sufficient. 直线钢轨（我们通常设计两个外形），首先用一个观察到状态良好的测量的直线外形，改变钢轨表面的半径，把匹配点的分布略微移动到中心偏轨距侧和中心侧适度的位置。两种设计的匹配分布点必须有一些重叠，以确保这两种设计的车轮踏面上的接触光带应力的没有更多的增加。多个直线钢轨外形可以使车轮踏面的磨耗更均匀，以延缓凹形车轮的形成。如果铁路/线路具有高密度的曲线路线，单一的钢轨外形就足够了。,31,轮轨相互作用的分析方法和轮轨外形的设计,Process for Wheel and Rail P
27、rofile Design轮轨外形的设计过程,10. Low rail designs generally require a large enough crown radius (250 mm is common for harder rails) to ensure low contact stresses with wheels. Field side relief can be designed-in to account for hollow wheels/false flanges if the railway has limited control over the wheel
28、shapes, but excessive field-side relief to deal with a hollowing problem just worsens the false flange problem. The gauge corner only needs enough relief to avoid contact with wheels from trailing axles that might shift towards the low rail. The design typically only needs to extend to 35 degrees ga
29、uge. 内轨的设计（轨顶区域）要求有足够大的圆弧半径（硬度较高的钢轨通常要达到250mm），以确保与车轮有小的接触应力。如果对车轮外形控制不好的情况下，考虑到车轮凹形磨耗/假轮缘，可以将钢轨外侧设计更低点。但是在处理凹轮问题时，将外侧设计过低，会恶化假轮缘问题。轨内侧只需要足够多的降低值，来避免导向轮转向内轨。这种（钢轨打磨模板外形的）设计通常只需要考虑到超过35轨距角。,32,轮轨相互作用的分析方法和轮轨外形的设计,Process for Wheel and Rail Profile Design轮轨外形的设计过程,Work with grinding contractors expert
30、 to design grinding patterns to best achieve these “as ground” shapes. 与打磨施工企业的专家一起来设计打磨形式，以达到最佳“打磨”钢轨形状。,Methods for Analysis of Wheel/Rail Interaction and Design of Wheel and Rail Profiles轮轨相互作用的分析方法和轮轨外形的设计,Michael Roney Consultant and retired Chief Engineer, Canadian Pacific With the assistance of Rob Caldwell, National Research Council of Canada 加拿大太平洋铁路公司的顾问和退休总工程师，加拿大国家研究委员会对罗布考德威尔援助,China Railway Corporation TECHNICAL WORKSHOP 中国铁路技术研讨会 16 October, 2015,34,轮轨相互作用的分析方法和轮轨外形的设计,