城际铁路无砟轨道选型及总体方案研究

针对城际铁路的特点,提出无砟轨道选型原则,通过方案比选推荐采用CRTSⅠ型双块式无砟轨道。对双块式无砟轨道的总体方案进行优化设计,提出时速160km/h及以下城际铁路桥梁地段双块式无砟轨道取消底座方案,并对其方案进行静动力学计算分析,计算结果表明,取消底座方案可行。     

高速铁路路基不均匀沉降对胶黏道砟道床过渡段的影响研究

以中兰客专某车站为例，采用ABAQUS有限元软件建立胶黏道砟道床过渡段的车辆-轨道-路基空间耦合模型，分析列车双向行驶时不平顺激励下折角沉降差异值的影响规律。研究结果表明：折角沉降差异值增大时，列车从无砟轨道至有砟轨道钢轨垂向振动位移与轮轨力增大幅度明显大于反向行驶；上行和下行钢轨垂向位移最大峰值点均处在折角沉降起点9 m的位置，而车体垂向加速度、轮轨垂向力上行和下行其峰值点位置均不相同。     

高速铁路不同结构类型曲线轨道的轮轨动态相互作用特征分析

为了研究高速铁路不同结构类型曲线轨道的轮轨动态相互作用特征,以期为动车组在线路上的适应性设计提供参考,通过动力学仿真的手段,针对我国高速铁路常见的的板式无砟轨道、双块式无砟轨道和有砟轨道等多种类型轨道结构,采用车辆-轨道耦合动力学模型,选取轨道随机不平顺和钢轨波浪形磨耗不平顺,计算了高速动车组通过曲线时的轮轨动态相互作用响应,分析了动车组在不同结构类型曲线轨道上运行的动态相互作用特征.结果表明,动车组在不同结构类型的曲线轨道上运行时,轮轨垂向动态相互作用指标随速度增大而增大,轮轨横向动态相互作用指标随速度增大呈先减小后增大的规律.随机不平顺作用下,动车组在不同结构类型曲线轨道上动力学性能很接近,其在无砟轨道上的运行性能略优于在有砟轨道上的运行性能;钢轨波浪形磨耗不平顺作用下,CRTSⅡ型无砟轨道上的轮轨动态相互作用最强,CRTSⅠ,CRTSⅢ和双块式无砟轨道次之,有砟轨道最弱.      

路基上减振双块式无砟轨道结构设计合理性分析

对于穿越居民建筑物和人口密集场所的铁路,为减少列车运行产生的振动与噪声对人们生活和工作的影响,减振型无砟轨道结构形式逐渐被广泛采用。以成渝客专途经的重庆市沙坪坝站改工程为依托,提出适合该站需求的减振双块式无砟轨道结构,并进行了设计。运用Ansys有限元分析软件对设计的路基上减振双块式无砟轨道结构进行受力分析。结果表明:该轨道结构强度和裂纹宽度均满足规范要求,在一定程度上说明该轨道结构设计的合理性。     

高速铁路列车荷载下钢轨平顺性影响因素分析

列车荷载作用下的钢轨变形曲线受列车荷载、轨道整体刚度、钢轨自身性能、扣件间距和温度力等因素的制约。文中运用有限单元法建立轨道简化模型,分析各种制约因素对轨道结构的影响程度。结果表明,随着列车荷载、轨道整体刚度的减小和钢轨重量的增大,钢轨的变形曲线也越来越平顺,而钢轨内部温度力和扣件间距的改变对钢轨的变形曲线影响很小,可忽略不计。     

钢弹簧浮置板轨道位移实测与分析

为评价钢弹簧浮置板轨道钢轨与浮置板位移的合理性，通过现场实测与动力学仿真计算，对比分析钢轨与浮置板在列车以不同速度通过时的位移变化，并且模拟了地铁正式运营后的最不利情况。研究结果表明:车速的改变对钢弹簧浮置板轨道钢轨与浮置板的垂向位移没有大的影响。列车荷载的增加及不平顺的恶化会导致轮轨之间的作用力加强，进而导致钢轨与浮置板的垂向位移增大。     

隧道内新型组合轨枕块式无砟轨道结构分析

针对复杂艰险山区铁路隧道内区段较为严重且整治难度较大的基础变形病害，提出了一种隧道内新型组合轨枕块式无砟轨道，能充分适应轨道下部基础的变形，并基于有限元法对该结构的不同参数进行了力学分析。结果表明:为保证钢轨垂横向位移及轨道结构各部分所受拉应力值较小，建议组合式轨枕块的长宽高分别为830，276，140 mm；凹槽的深度宽度分别为80，970 mm；凸出高度为60 mm；为保证结构的整体性，建议组合式轨枕块选取聚氨酯材料；列车在新型组合轨枕式无砟轨道上运行时，其安全性与平顺性均满足要求。     

有砟轨道动刚度特性及影响因素分析

应用轨道结构的动力学频域分析方法,研究了有砟轨道的动刚度特性及轨道参数对它的影响。有砟轨道动刚度随频率变化幅度很大,在激振频率为72 Hz时达到最小值55 kN/mm,约为静刚度的60 %。扣件刚度、扣件阻尼、轨枕类型、道床弹性模量对有砟轨道动刚度都有影响。     

重载铁路隧道内弹性支承块式无砟轨道结构优化研究

为解决现有弹性支承块式无砟轨道动态轨距变化量大、轨道几何形位的保持能力相对较弱的问题，提出一种斜坡型弹性支承块式无砟轨道。采用静力计算方法，通过分析钢轨和支承块变形、支承块相对支承块槽的位移以及支承块和道床板的受力状态，研究弹性支承块短侧面的合理坡度； 基于模拟落轴试验，研究斜坡型弹性支承块式无砟轨道部件刚度匹配问题。研究表明： 斜坡型弹性支承块对于控制轨道结构变形，改善支承块、橡胶套靴及道床板等轨道结构受力状态更加有利。建议在30 t轴重条件下，弹性支承块短侧面坡度取1∶5~1∶6，套靴刚度取200 kN/mm左右，块下垫板刚度取80 kN/mm左右较为合理。     

长大隧道双块式无砟轨道施工测量

双块式无砟道床施工测量精度要求较高,测量手段和方法较先进。通过GEDO CE轨检小车在铁路长大隧道双块式无砟轨道施工中的应用,对双块式无砟轨道施工测量的原理、方法、步骤进行了阐述和探讨。得出： 1）无砟道床达到设计功能的关键在于精调测量的过程控制; 2）静态精调中最主要的指标是对10 m弦长的轨道高低和轨向的控制,这2项指标的变化率将直接影响列车的动态检核验收。     

High-frequency random vibration analysis of a high-speed vehicle–track system with the frequency-dependent dynamic properties of rail pads using a hybrid SEM–SM method

A hybrid Spectral Element Method (SEM)–Symplectic Method(SM) method for high-efficiency computation of the high-frequency random vibrations of a high-speed vehicle–track system with the frequency-dependent dynamic properties of rail pads is presented. First, the Williams-Landel-Ferry (WLF) formula and Fractional Derivative Zener (FDZ) model were, respectively, applied for prediction and representation of the frequency-dependent dynamic properties of Vossloh 300 rail pads frequently used in China's high-speed railway. Then, the proposed hybrid SEM–SM method was used to investigate the influence of the frequency-dependent dynamic performance of Vossloh 300 rail pads on the high-frequency random vibrations of high-speed vehicle–track systems at various train speeds or different levels of rail surface roughness. The experimental results indicate that the storage stiffness and loss factors of Vossloh 300 rail pad increase with the decrease in dynamic loads or the increase in preloads within 0.1–10,000?Hz at 20°C, and basically linearly increase with frequency in a logarithmic coordinate system. The results computed by the hybrid SEM–SM method demonstrate that the frequency-dependent viscous damping of Vossloh 300 rail pads, compared with its constant viscous damping and frequency-dependent stiffness, has a much more conspicuous influence on the medium-frequency (i.e. 20–63?Hz) random vibrations of car bodies and rail fasteners, and on the mid- (i.e. 20–63?Hz) and high-frequency (i.e. 630–1250?Hz) random vibrations of bogies, wheels and rails, especially with the increase in train speeds or the deterioration of rail surface roughness. The two sensitive frequency bands can also be validated by frequency response function (FRF) analysis of the proposed infinite rail–fastener model. The mid and high frequencies influenced by the frequency-dependent viscous damping of rail pads are exactly the dominant frequencies of ground vibration acceleration and wheel rolling noise caused by high-speed railways, respectively. Even though the existing time-domain (or frequency-domain) finite track models associated with the time-domain (or frequency-domain) fractional derivative viscoelastic (FDV) models of rail pads can also be used to reach the same conclusions, the hybrid SEM–SM method in which only one element is required to compute the high-order vibration modes of infinite rail is more appropriate for high-efficiency analysis of the high-frequency random vibrations of high-speed vehicle–track systems.     

Vossloh300扣件阻尼频变对高铁高频振动的影响研究

以Vossloh300扣件胶垫为研究对象，利用配备温度箱的万能试验机测得其在-60℃~20℃的耗能刚度。在试验基础上结合温频等效原理及车辆-轨道垂向耦合Timoshenko梁模型，在频域内探究该型扣件频变阻尼对高铁轮轨系统动力特性的影响。结果表明:Vossloh300扣件胶垫在20℃，4 Hz激振频率下阻尼系数约152.2 kN/（m·s-1）。Vossloh300扣件频变阻尼主要影响车辆-轨道垂向耦合系统1/3倍频中心频率22 Hz以上的振动响应，即:①增大车辆和轨道系统22~56 Hz的中高频振动，同时减小其60~256 Hz的高频振动；②在512~1 500 Hz范围内，钢轨垂向1/3倍频加速度振级最大值增大了5 dB，同时，扣件力1/3倍频幅值最大值减小了92%。因此，为精确预测高速铁路车辆及轮下结构随机振动响应，需考虑扣件胶垫的阻尼频变特性。     

隧道内长枕式无砟轨道结构性能分析

针对长大隧道内轨道养护维修困难、基础上拱变形、病害整治难度大的问题,在弹性长枕式无砟轨道的基础上优化,提出了隧道内长枕式无砟轨道,通过扣件和枕下垫板组成的双调高系统进行垂向调高;基于有限元法和车辆-轨道耦合动力学理论,对其进行受力状态和参数分析.结果 表明:隧道内长枕式无砟轨道可通过更换枕下垫板实现向下80 mm的调整...     

Dynamic Train-Track Interaction: Variability Attributable to Scatter in the Track Properties

A numerical method to simulate vertical dynamic interaction between a rolling train and a railway track has been used to investigate the influence of stochastic properties of the track structure. A perturbation technique has been used to investigate the influence of the scatter in selected track properties. The train-track interaction problem has been numerically solved by use of an extended state-space vector approach in conjunction with a complex modal superposition for the whole track structure. All numerical simulations have been carried out in the time-domain with a moving mass model. Properties such as rail pad stiffness, ballast stiffness, dynamic ballast-subgrade mass and sleeper spacing have been studied. To obtain sufficient statistical information from track structures, full-scale measurements in the field and laboratory measurements have been carried out. The influence of scatter in the track properties on the maximum contact force between the rail and the wheel, the maximum magnitude of the vertical wheelset acceleration, and the maximum sleeper displacement have been studied. Mean values and standard deviations of these quantities have been calculated. The effects of the variation of the investigated track properties are discussed.     

Dynamic Train-Track Interaction: Variability Attributable to Scatter in the Track Properties

A numerical method to simulate vertical dynamic interaction between a rolling train and a railway track has been used to investigate the influence of stochastic properties of the track structure. A perturbation technique has been used to investigate the influence of the scatter in selected track properties. The train-track interaction problem has been numerically solved by use of an extended state-space vector approach in conjunction with a complex modal superposition for the whole track structure. All numerical simulations have been carried out in the time-domain with a moving mass model. Properties such as rail pad stiffness, ballast stiffness, dynamic ballast-subgrade mass and sleeper spacing have been studied. To obtain sufficient statistical information from track structures, full-scale measurements in the field and laboratory measurements have been carried out. The influence of scatter in the track properties on the maximum contact force between the rail and the wheel, the maximum magnitude of the vertical wheelset acceleration, and the maximum sleeper displacement have been studied. Mean values and standard deviations of these quantities have been calculated. The effects of the variation of the investigated track properties are discussed.     

基于车内瞬变压力变化的400 km/h高速铁路隧道净空面积探讨

为推进中国高速铁路隧道技术标准深化研究,开展400 km/h隧道结构设计参数的研究工作,而隧道净空面积为其中的一项重要内容。为尝试从列车内部瞬变压力角度得到400 km/h高速铁路隧道净空面积,建立基于舒适度标准的高速铁路隧道净空面积确定方法,以控制工况为基础,通过计算和分析,从列车密封性能方面讨论维持现有隧道净空断面的可能性,并研究提出400 km/h隧道净空断面建议值。主要结论有:1)现有350 km/h单线隧道以400 km/h运营时,列车动态密封指数最低为22 s,车内瞬变压力超标的可能性较大; 2)400 km/h单、双线隧道净空面积建议值分别为85 m~2和100 m~2,对应的列车动态密封指数最低为18 s,更加符合现有标准对列车密封性能的要求,车内瞬变压力超标的可能性大幅降低; 3)提出的400 km/h高速铁路隧道净空面积建议值和对应的密封性能要求可为有关标准、规范的制订提供参考。     

Conceptual design of high-speed semi-low-floor bogie for train-tram

Train-tram railway vehicles implement the connection between urban tramlines and the surrounding railway network. Train-tram railway vehicles, which use existing infrastructure, can help to avoid large investments in new railways or tramlines and make interchanges between city center and surrounding cities unnecessary. However, present train-tram rail vehicle cannot carry out the integration of operating by means of high speed in intercity railways with operating on small radius of curvature in inner city tramlines. This paper aims to develop a new model for solid wheelsets train-tram railway vehicles, which will not only pass the curve of 25mR radius of curvature traveling on inner city tramlines with the speed of 18 km/h, but also can travel on straight railway with 200 km/h high speed between intercity. In this paper, a new train-tram model, including five car-body and five motor bogies with ten traction motors, is addressed. Expect as a real rail vehicle testing, this study prefer virtual simulation, which is an effective way to show the rail vehicle performance, such as ride stability, ride comfort and ride safety, by means of evaluating the dynamic characteristics of rail vehicle. Moreover, Design of Experiment (DOE) method is used to optimize solid wheelsets bogie system on improving passenger comfort, safety and stability of train-tram. Parameters of components of bogie system are tuned to minimize the derailment coefficient and the ride comfort index. The results shows that the best comfort index for passenger and minimum derailment coefficient are found. The results also show that this optimized new train-tram model is reliable and practical enough to be applied on real rail vehicle design.     

Wheel/Rail Non-linear Interactions With Coupling Between Vertical and Lateral Directions

Summary A theoretical model is developed to explore the high frequency wheel/rail interaction with coupling between the vertical and lateral directions. This coupling is introduced through the track dynamics due to the offset of the wheel/rail contact point from the rail centre line. Equivalent models of the railway track in the time domain are developed according to the rail vibration receptances in the frequency domain. The wheel is represented by a mass in each direction with no vertical-lateral coupling. The vertical wheel/rail interaction is generated through a non-linear Hertzian contact stiffness, allowing for the possibility of loss of contact between the wheel and rail. The lateral interaction is represented by a contact spring and a creep force damper in series and their values depend on the vertical contact force. The vibration source is the roughness on the wheel and rail contact surfaces which forms a relative displacement excitation in the vertical direction. Using the combined interaction model with this relative displacement excitation, the wheel/rail interactions with coupling between the vertical and lateral vibrations are simulated. It is found that the lateral interaction force caused by the offset is usually less than thirty percent of the vertical dynamic force. The lateral vibration of the rail is significantly reduced due to the presence of the lateral coupling, whereas the vertical interaction is almost unaffected by the lateral force.     

Dynamic vehicle–track interaction in switches and crossings and the influence of rail pad stiffness – field measurements and validation of a simulation model

A model for simulation of dynamic interaction between a railway vehicle and a turnout (switch and crossing, S&C) is validated versus field measurements. In particular, the implementation and accuracy of viscously damped track models with different complexities are assessed. The validation data come from full-scale field measurements of dynamic track stiffness and wheel–rail contact forces in a demonstrator turnout that was installed as part of the INNOTRACK project with funding from the European Union Sixth Framework Programme. Vertical track stiffness at nominal wheel loads, in the frequency range up to 20?Hz, was measured using a rolling stiffness measurement vehicle (RSMV). Vertical and lateral wheel–rail contact forces were measured by an instrumented wheel set mounted in a freight car featuring Y25 bogies. The measurements were performed for traffic in both the through and diverging routes, and in the facing and trailing moves. The full set of test runs was repeated with different types of rail pad to investigate the influence of rail pad stiffness on track stiffness and contact forces. It is concluded that impact loads on the crossing can be reduced by using more resilient rail pads. To allow for vehicle dynamics simulations at low computational cost, the track models are discretised space-variant mass–spring–damper models that are moving with each wheel set of the vehicle model. Acceptable agreement between simulated and measured vertical contact forces at the crossing can be obtained when the standard GENSYS track model is extended with one ballast/subgrade mass under each rail. This model can be tuned to capture the large phase delay in dynamic track stiffness at low frequencies, as measured by the RSMV, while remaining sufficiently resilient at higher frequencies.     

Study on rail corrugation of a metro tangential track with Cologne-egg type fasteners

In Chinese metro lines, rail corrugation on both tangential and tight curved tracks with Cologne-egg type fasteners is very severe. Based on the viewpoint of friction-induced vibration causing rail corrugation, the rail corrugation on a tangential track with Cologne-egg type fasteners is studied in this paper. A vibration model of an elastic multiple-wheelset-track system with Cologne-egg type fasteners is established. Both the complex eigenvalue analysis and the transient dynamic analysis are performed to study the stability and the dynamic performance of the wheelset-track system. The simulation results show that a low rail support stiffness value is responsible for rail corrugation on the tangential track. When the Cologne-egg fasteners characterised by a lower stiffness value are replaced with the DTVI2 fasteners characterised by a higher stiffness value, rail corrugation disappears. However, rail corrugation on tight curved tracks cannot be suppressed using the same replacement. The above conclusions are consistent with the corrugation occurrences in actual metro tracks.