铁道车辆滚动振动试验台动态曲线模拟方法

曲线通过性能对于保障车辆长期安全运行具有重要影响,而室内整车滚振试验是一种对该性能预测、优化的高效手段。车辆曲线线路运行时,线路内外轨具有长度差、超高和曲线半径沿轨道弧坐标而变化,同时还受到离心力作用,在考虑上述因素情况下,提出一种通过室内滚振试验台来模拟曲线线路运行的试验方法,并进行可行性验证。分析表明,除去缓和曲线与圆曲线交接处的瞬时冲击作用,滚振台工况在轮对摇头角、接触点位移以及脱轨系数、轮轨横向力、磨耗功等特征在直线段、缓和曲线段、圆曲线段均能较好模拟线路工况,二者误差控制在7%以内。从工程角度看,所提出的滚动振动试验台动态曲线模拟方法是可行的,可为进一步建立具有动态曲线模拟功能的滚振试验台提供理论依据。     

D19E型内燃机车曲线通过动力学性能研究

为了研究D19E型内燃机车曲线通过动力学性能,分析了越南铁路基本技术及D19E型内燃机车结构,应用Simpack软件建立了D19E型内燃机车动力学模型。以D19E为模型计算了机车动态曲线通过整车动力学性能,并根据越南铁道机车车辆动力学性能评定规范对该机车车辆在轨道不平顺作用下的不同工况曲线通过进行了分析、评估。研究结果表明,D19E型内燃机车动态曲线通过时的安全性指标满足越南铁路安全行车要求,该机车通过曲线半径为100 m时轮轨横向力接近了允许限值52 kN,在曲线半径为300 m以下时轮重减载率超过静态轮重减载率危险限度值0.65,但动态轮重减载率为0.8,故属合格,因此该机车通过曲线半径小于300 m时应降低运行速度,机车曲线通过更为安全。     

采用计算机测控的新型ABS试验台的设计

以机电混合模拟技术为理论基础[1],分析建立了汽车运动惯量和道路制动力台架电模拟数学模型,以LabVIEW软件为平台,运用动态链接库技术,建立了新型的ABS试验台。该试验台通过计算机技术对车轮制动过程进行实时测控。试验结果表明:试验台能较好地模拟车辆在不同路面下的制动情况,为ABS性能测试分析提供了较好的手段。     

基于室内六通道汽车零部件道路模拟研究

多轴模拟试验台(multi-axial simulation table,MAST)系统用六通道模拟试验台系统模拟汽车零部件在空间的六个自由度运动状态,精确地在试验台上再现汽车零部件的实际运行环境.通过对发动机支承实际道路载荷的采集、整理迭代计算得到了用于台架试验的加载谱,其结果可对发动机支承进行可靠性试验和动态性能试验.     

横风作用下的高速磁浮列车曲线通过性能研究

针对横风对高速磁浮列车曲线通过性能的影响问题,以我国高速磁浮列车为原型,建立了 204自由度的车辆轨道垂横耦合模型,施加横风载荷和轨道方向不平顺激励,对列车满载通过曲线线路的工况进行数值模拟.仿真计算和对比分析结果表明:横风作用时,风力引起的迎风侧磁场间隙变小是影响列车安全运行的重要因素.横风效应使列车在单侧压力下的动力学性能呈现相当强的非对称性,迎风侧和背风侧的系统结构振动响应相差很大.曲线通过时,风向从外侧向内比从内侧向外,运行平稳性更差.横风风速小于10 m/s时,各项动力学性能指标变化不大.在风速大于15 m/s后,横风风速对车辆系统动力学的影响超过超高情况、车速和轨道方向不平顺,起主导作用.     

摩托车制动器试验台电模拟惯量的研究

对电惯量模拟方法进行了深入分析,通过对制动过程中制动力矩的分析,给出了电机在制动器制动时输出的力矩与模拟惯量的关系.采用机械模拟和电模拟相结合的方法设计开发了摩托车制动器试验台,实现制动器台架试验时对当量惯量的模拟.试验表明:采用电惯量模拟后,系统的性能明显优于采用大量飞轮的机械惯量制动器试验台,提高了试验台的自动化程度.     

轴箱振动计算轨道不平顺方法研究

为实现在既有运营线路上动态测量轨道不平顺,对通过轴箱的加速度信息计算轨道不平顺的方法进行研究。分析了在时域和频域上使用轴箱加速度轨道不平顺的计算方法,并在同济大学轨道交通实验线上进行实验测试。分别使用频域和时域计算法对测试数据进行分析处理,得到轨道不平顺。对使用上述两种方法的计算结果进行验证比较和理论分析。实验结果表明,通过轴箱上的加速度进行计算能够反映轨道上的不平顺情况,并且在时域上计算的效果更好。     

轮轨几何接触的通解研究

从轮轨几何接触的最一般情况入手,分析并建立轮轨接触几何通解的模型;考虑轮对的横移和摇头对几何接触的影响,并考虑轮对在曲线轨道上运动时,动态轨道即轨道曲率、扭率、轨头翻转、轨道倾角的动态变化及轨道几何不平顺的动态变化等对几何接触的影响;同时考虑左右轮轨型面不对称的情况;得出了轮轨接触几何通解的方程式并给出了部分数值模拟结果。     

基于LabVIEW的航空轴承摩擦学性能模拟实验系统

航空轴承具备高速、高载、高温的运行特性，在其服役过程中摩擦学的状态演变对其性能衰变有着重要的影响。为实现航空轴承摩擦学状态参数的动态监测，设计一种基于LabVIEW环境下的航空轴承试验台摩擦学性能状态模拟测控系统，通过人机界面（HMI）对航空轴承的服役过程进行环境的模拟预设，由驱动系统执行动作指令，过程中由动态监测单元获取实验过程中的摩擦学动态数据链，实现高性能测量、基于FPGA的高级分析与控制；并根据动态的数据链利用LabVIEW中的NI软运动技术，以获取更为贴合运行工况的真实模拟，实现PID控制到高级的动态智能控制系统。试验表明，设计的航空轴承试验台摩擦学性能测控系统，能够很好地获取航空轴承在复杂工况下的性能演变过程中的摩擦磨损信息，从而实现对航空轴承的动态性能评价。     

三模块编组有轨电车抗折弯装置设计

介绍了三模块编组100%低地板有轨电车抗折弯系统,从原因、功能、构成和运行模式等方面对抗折弯系统进行说明,同时对抗折弯系统的工作原理进行了详细的分析。轨道车辆在运行过程中,由于轨道不平顺的影响,往往会产生复杂的振动现象。系统有抗折弯和横摆及摇头减振两大功能,提高了列车的运动稳定性,运行平稳性和曲线通过性能。     

A study on the dynamic performance of the 200km/h Korean tilting train by means of roller rig test

The dynamic performances of newly developed railway vehicles should be carefully verified step by step, from computer simulation through the laboratory-based roller rig test to the main line trial running test. The laboratory-based roller rig test is an effective and safe way to evaluate the dynamic characteristics such as high speed, ride comfort and dynamic behaviors. This experimental research was performed to evaluate the dynamic performances of the 200 km/h Korean tilting train, ‘Hanvit200’, by means of a full scale roller rig test. The newly developed tilting mechanism and stabilizer were included in the tilting bogie to satisfy both the conflicting requirements of higher stability and higher curving performance. This paper shows the roller rig test results and the effectiveness of tilting bogie design. Included are the roller rig test results of various kinds of conditions such as tare and fully laden load case, normal and failed case of important bogie components, linear and non-linear critical speed. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Nam-Po Kim received a B.S. degree in Mechanical Engineering from Ajou University in 1985. He then went on to receive his M.S. and Ph.D. degrees from Ajou University in 1992 and 2008, respectively. Dr. Kim is currently a principal researcher at the department of vehicle dynamics and propulsion system at Korea Rail Road Research Institute in Uiwang, Korea. His research interests are in the area of railway vehicle dynamics, active control of running gear for railway vehicle and vehicle system engineering.     

一种新的铁道车辆滚振试验台曲线通过试验方法

推导了车辆在通过曲线时的轮轨蠕滑率计算公式,并建立模拟铁道车辆曲线通过的滚振台非线性动力学模型,提出一种新的曲线通过台架试验方法,并分析了不同试验方法对车辆轮轨垂向力的影响。研究结果表明：滚动台上的车辆系统经由未平衡至平衡状态的过程中,现行的曲线通过试验方法冲击过大,而新的试验方法可以很好地避免这种冲击;将根据两种试验方法计算得到的安全性指标与曲线线路的结果进行对比可知,三者的变化规律一致;在两种试验方法的安全性指标对比中,新的试验方法与线路结果的误差更小,说明所提出的曲线通过试验方法是可行的。     

Parametric study of lateral stability for a railway vehicle

This paper deals with the lateral stability for a railway vehicle. Particularly, nonlinear critical speed is investigated via bifurcation analysis. Shooting method and trust region algorithm are applied to calculate the limit cycle of the nonlinear dynamic vehicle model. In case of the investigated vehicle model, the influences of the suspension parameters on the critical speeds are not large. The effects of friction coefficient are also small. However, there is an overall consistency that the nonlinear critical speed is decreased when the stiffness of the suspension is reduced. Study of the excitation conditions where the stable limit cycles occur gives very useful information to understand the nonlinear dynamic behavior of a railway vehicle and to test the vehicle with roller rig test stands. According to the results, the direction of the excitation is very important as well as the amplitude and frequency to acquire accurate nonlinear critical speed.     

Design and analysis of an active steering bogie for urban trains

The conventional railway vehicle was designed to ensure running stability using high stiffness elements for primary suspensions. Curving performance of the railway vehicle is relatively low because the natural steering motion of a wheelset is constrained by the high stiffness suspensions. High running stability has always been in conflict with good curving performance in conventional design processes. This conflict problem can be solved with an active steering bogie since active elements properly control the wheelset motions according to track conditions such as straight or curved lines. In this paper, an active steering mechanism for railway vehicle is introduced, and the curving performance of the proposed active steering bogie is investigated through simulation and experiments. According to the results, the proposed active steering bogie is highly effective for curve negotiation.     

Semi-active control to reduce carbody vibration of railway vehicle by using scaled roller rig

As train operating speeds increase, upgrading the performance of the railway vehicle has been required. To improve the ride comfort related to vibration, researches to replace the conventional passive suspension with (semi)active suspension have been carried out. For the purpose of vibration reduction, the magneto-rheological (MR) damper has been widely applied in automobile or anti-vibration areas, but it hasn??t yet been applied to railway vehicles. In this study, skyhook control with the MR damper was applied to the 1/5 scaled railway vehicle model on roller rig to suppress the lateral vibration of the carbody. For the 1/5 scaled prototype model of the railway vehicle, the dimensions of railway vehicle were scaled down by similarity method. Both numerical analysis and experiments to control the carbody lateral vibration were conducted and compared. The possibility of improving both the ride comfort and running stability of the railway vehicle by using the semi-active control was discussed in detail.     

滚动振动试验台状态误差对机车车辆稳定性试验结果的影响

介绍了我国自行研制的机车车辆滚动振动试验台及机车车辆运动稳定性试验方法。针对滚动振动试验台状态可能出现的误差,结合160km/h准高速客车,利用车辆非线性系统运动稳定性求解方法,得到了不同试验台状态条件的极限环图,通过比较其蛇行失稳临界速度,找出这些试验台状态误差对机车车辆运动稳定性试验结果影响状况。     

Experimental analysis of factors influencing the cage slip in cylindrical roller bearing

This paper deals with the effect of operating parameters on cage slip in cylindrical roller bearing. A cylindrical roller bearing test rig is developed to measure the running speed of bearing elements at various operating conditions. The effect of operating parameters namely shaft speed, radial load, viscosity of lubricating oil, number of rollers, and bearing temperature on cage slip are experimentally obtained. The critical load and magnitude of cage slip for various operating conditions are obtained. The non-dimensional number is derived based on the operating parameters. The region where cage slip occurs is developed from the derived non-dimensional number and the experimental data. The temperature raise is experimentally obtained during slip condition and its effect on viscosity is included for calculations. The frictional forces are experimentally obtained and are compared with the theoretical findings. The significant effect of operating parameters on cage slip of cylindrical roller bearing is discussed based on the experimental findings.     

[轮轨磨耗及预测]弹性车轮作用下低地板有轨电车轮轨磨耗研究

为研究使用弹性车轮的车辆踏面以及运行弹性车轮的钢轨磨耗情况,基于Archard磨耗模型建立了轮轨磨耗预测模型,对不同轨道不平顺条件、不同曲线半径条件下的车轮踏面以及钢轨磨耗情况进行了分析。对比分析弹性车轮和刚性车轮,结果表明：在线路较差的情况下,弹性车轮具有更好的降磨效果;弹性车轮在曲线半径较小的线路上对磨耗的降低效果较小,随着曲线半径的增大,弹性车轮的降磨效果明显;运行弹性车轮时比运行刚性车轮时钢轨的最大累积磨耗量减小了33%;弹性车轮对曲线钢轨磨耗有一定的降低作用。     

基于转向架姿态轨迹的轨道线路曲率探测系统研究

主动径向技术是进一步提高轨道车辆曲线通过性能、彻底解决直线运行稳定性和曲线通过之间矛盾的有效途径,而实现轨道线路曲率准确、高效的探测是其中的重要环节。为了提高轨道线路曲率探测的精度和实时性,首先提出了一种基于转向架姿态轨迹的曲率探测系统(Bogie attitude trajectory based curvature detection system,BATCDS),该系统由布置于转向架上的速度传感器、角速度传感器、倾角传感器以及算法单元组成,布局简单且易于实现。此后,提出了与上述系统相匹配的曲率探测算法,该算法利用转向架偏航角速度ω和车速v获取转向架在二维水平面上的运行轨迹,并据此初步估计线路曲率;利用转向架侧滚角α和车速v获取转向架的侧滚姿态轨迹,进而估计转向架侧滚角;综合转向架上述各项姿态信息,利用轨道线路固有几何规律融合计算线路曲率。最后,建立了BATCDS的联合仿真模型,仿真计算的结果表明,该系统在有效滤除原始信号中的高频噪声的基础上,仍能维持较高的实时性;仿真工况下,相较传统的低通滤波而言曲率探测结果的精度和实时性得到显著改善,相对误差率均降低至传统方法的50%以下,最大...     

构架结构振动与动态应力仿真研究

首先利用有限单元法,建立了详细的构架有限元模型并求解其各阶振动模态,在此基础上建立了完整的刚—弹性体车辆系统动力学模型;通过动力学模拟计算得到了构架在车辆曲线通过和随机激扰下的结构振动响应;最后,将构架的动力学计算结果返回到有限元中,得到了构架的动态应力时间历程与分布特性。该种研究方式不仅完成了多体系统动力学研究中刚体与弹性体的有机结合,而且为转向架在结构设计阶段通过模拟计算就可获得车辆运行过程中构架的动态应力分布,为评估其疲劳寿命奠定了基础。该仿真技术同样实用于其他相关研究领域,如航空航天、工程机械和公路车辆等。