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1.
A high-speed train-track coupling dynamic model is used to investigate the dynamic behavior of a high-speed train operating on a curved track with failed fasteners. The model considers a high-speed train consisting of eight vehicles coupled with a ballasted track. The vehicle is modeled as a multi-body system, and the rail is modeled with a Timoshenko beam resting on the discrete sleepers. The vehicle model considers the effect of the end connections of the neighboring vehicles on the dynamic behavior. The track model takes into account the lateral, vertical, and torsional deformations of the rails and the effect of the discrete sleeper support on the coupling dynamics of the vehicles and the track. The sleepers are assumed to move backward at a constant speed to simulate the vehicle running along the track at the same speed. The train model couples with the track model by using a Hertzian contact model for the wheel/rail normal force calculation, and the nonlinear creep theory by Shen et al. (1984) is used for wheel/rail tangent force calculation. In the analysis, a curved track of 7000-m radius with failed fasteners is selected, and the effects of train operational speed and the number of failed fasteners on the dynamic behaviors of the train and the track are investigated in detail. Furthermore, the wheel/rail forces and derailment coefficient and the wheelset loading reduction are analyzed when the high-speed train passes over the curved track with the different number of continuously failed fasteners at different operational speeds. Through the detailed numerical analysis, it is found that the high-speed train can operate normally on the curved track of 7000-m radius at the speeds of 200 km/h to 350 km/h. 相似文献
2.
An online experiment to acquire the interior noise of a China Railways High-speed (CRH) train showed that it was mainly composed of middle-low frequency components and could not be described properly by linear or A-weighted sound pressure level (SPL). Thus, the appropriate way to evaluate the high-speed train interior noise is to use sound quality parameters, and the most important is loudness. To overcome the disadvantages of the existing loudness algorithms, a novel signal-adaptive Moore loudness algorithm (AMLA) based on the equivalent rectangular bandwidth (ERB) spectrum was introduced. The validation reveals that AMLA can obtain higher accuracy and efficiency, and the simulated dark red noise conforms best to the high-speed train interior noise by loudness and auditory assessment. The main loudness component of the interior noise is below 27.6 ERB rate (erbr), and the sound quality of the interior noise is relatively stable between 300–350 km/h. The specific loudness components among 12–15 erbr stay invariable throughout the acceleration or deceleration process while components among 20–27 erbr are evidently speed related. The unusual random noise is effectively identified, which indicates that AMLA is an appropriate method for sound quality assessment of the high-speed train under both steady and transient conditions. 相似文献
3.
This paper presents a detailed investigation, via field experiment, into the mechanism of high-order polygonal wear of wheels of a new type of high-speed train. The investigation was carried out during the performance acceptance test of the train and its initial commercial operation. The investigation covered the performance acceptance test of 150 000 km and the commercial operation of about 150 000 km. In the performance acceptance test of the first stage of about 70 000 km, at 200–250 km/h with full loading and sometimes overloading by 30%, the serious polygonal wear of 23-order took place on all the wheels of the train, and was measured and analyzed in detail. All the polygonized wheels were re-profiled because the polygonal wear had caused strong vibration and damage to the train parts. After re-profiling, the vibration of the train and track and the wear status of the wheels were measured and analyzed at different test mileages according to the polygonal wear situation of the wheels. The measured vibration of the train includes the accelerations at different positions of a motor car and a trail car. The vibration modes of the key parts of the bogies of the two cars were calculated. Meanwhile, the track resonant frequencies were investigated at the site. The purpose of the above tests and analysis is try to find the frequency of work mode matching the passing frequency of the high-order wheel polygon. The present investigation shows that one of the working models causes the formation and development of the high-order wheel polygonal wear. The growth of this wear was effectively reduced through the frequent changing of the running speed of the train operating on the way back and forth every day. 相似文献
4.
Jie ZHANG ;Guang-xu HAN ;Xin-biao XIAO ;Rui-qian WANG ;Yue ZHAO ;Xue-song JIN 《浙江大学学报(A卷英文版)》2014,(12):1002-1018
研究目的：研究高速列车车轮多边形特征对轮轨噪声和车内噪声的影响规律,讨论目前国内高速列车车轮镟修指标的不足,为高速列车车轮镟修方法的优化改进提供科学依据。创新要点：系统分析高速列车车轮多边形阶次、幅值和相位等参数对车内噪声的影响规律;提出车轮镟修中仅考虑车轮径跳作为限值是不够的。研究方法：1．基于线路试验,初步分析高速列车车轮多边形状态对车内噪声的影响,进而对车轮多边形特征进行剖析;2．基于带通滤波和快速傅里叶变换,使用MATLAB程序生成不同阶次、幅值和相位的车轮多边形粗糙度数据;3．基于TWINS轮轨噪声原理,使用HWTNS预测含有不同车轮多边形特性的轮轨噪声;4．基于混合有限元-统计能量分析（FE—SEA）方法,建立高速列车客室端部车内噪声预测模型,预测车内噪声;5．通过分析车轮多边形参数、车轮径跳和车内噪声之间的相互关系,研究目前的高速列车车轮镟修指标是否合适。重要结论：1．高速列车车轮径跳值相同,但车轮多边形状态不同时,轮轨噪声与车内噪声有明显差异;2．当车轮多边形幅值相同时,高阶多边形可以引起更高的轮轨噪声和车内噪声;3．改变车轮多边形的相位,可以获得不同的车轮径跳值,但是对轮轨噪声和车内噪声几乎没有影响。 相似文献
5.
不同速度高速列车车外噪声的调查研究 总被引：1，自引：1，他引：0
Bin HE Xin-biao XIAO Qiang ZHOU Zhi-hui LI Xue-song JIN 《浙江大学学报(A卷英文版)》2014,(12):1019-1033
研究目的：基于声源识别,得出车外噪声分布特性及场点主要噪声源。创新要点：1．研究高速列车噪声源强特性及频谱特性;2．揭示不同速度下不同声源频谱变化规律;3．分析车外声场场点噪声变化规律及主要声源。研究方法：1．利用车外声源识别系统（图2）分析高速列车声源分布规律及频谱特性;2．利用声源的垂向（图10）分布研究不同声源在各频率下垂向分布规律;3．利用场点声源与速度的拟合关系（图16）研究场点主要噪声源。重要结论：1．高速列车车外噪声源主要分布在轮轨区域、受电弓和车间连接区域;2．轮轨区域噪声包括滚动噪声和气动噪声,在各频率均为最显著声源;3．在整个列车高度,轮轨滚动噪声对总噪声贡献率大于气动噪声;4．车外场点噪声主要频率为630-2500Hz,主要来自轮轨滚动噪声。 相似文献
6.
高速铁路运营过程中的关键问题：轮轨磨耗等 总被引：1，自引：0，他引：1
Xue-song JIN 《浙江大学学报(A卷英文版)》2014,(12):936-945
随着高速铁路运营里程和列车运营速度的不断增长,出现了一些和列车轨道耦合大系统密切相关的关键科学和技术问题。这些问题不仅影响到列车的运行品质,甚至威胁到安全运行,是当前高速铁路运用和发展中急需解决的问题。本文系统描述了高速铁路在运营过程中所出现的一些关键科学和技术问题,并述评了全世界有关这些问题的研究进展、现状和不足之处,提出了今后有利于认识和解决这些问题的发展方向。在长期高速运营的铁路大系统环境中,这些问题的形成的机理、发生、发展过程和预防措施的研究,需要从列车／轨道耦合大系统运营环境（速度、路况、气候和运用维修）、系统的自身参数匹配、材料选用和运营成本等全面系统考虑,并从理论、技术、工艺、监控和维修等方面解决。 相似文献
7.
Aerodynamic forces and dynamic performances of railway vehicles are coupled and affected by each other. On the one hand, aerodynamic forces change the displacements of a train. On the other hand, displacements affect aerodynamic forces. Based on vehicle-track coupling dynamics and aerodynamics, a numerical approach to the interaction between airflow and a high-speed train is presented in this paper. Aerodynamic forces and dynamic performances of a high-speed train subjected to crosswind were numerically simulated. Results showed that the interaction between airflow and a high-speed train has a significant influence on displacements and aerodynamic forces of the head coach. Therefore, it is necessary to consider the interaction between airflow and a high-speed train subjected to crosswind. 相似文献
8.
To improve the aerodynamic performance of high-speed trains (HSTs) running in the open air, a multi-objective aerodynamic optimization design method for the head shape of a HST is proposed in this paper. A parametric model of the HST was established and seven design variables of the head shape were extracted. Sample points and their exact values of optimization objectives were obtained by an optimal Latin hypercube sampling (opt. LHS) plan and computational fluid dynamic (CFD) simulations, respectively. A Kriging surrogate model was constructed based on the sample points and their optimization objectives. Taking the total aerodynamic drag force and the aerodynamic lift force of the tail coach as the optimization objectives, the multi-objective aerodynamic optimization design was performed based on a non-dominated sorting genetic algorithm-II (NSGA-II) and the Kriging model. After optimization, a series of Pareto-optimal head shapes were obtained. An optimal head shape was selected from the Pareto-optimal head shapes, and the aerodynamic performance of the HST with the optimal head shape was compared with that of the original train in conditions with and without crosswinds. Compared with the original train, the total aerodynamic drag force is reduced by 2.61% and the lift force of the tail coach is reduced by 9.90% in conditions without crosswind. Moreover, the optimal train benefits from lower fluctuations in aerodynamic loads in crosswind conditions. 相似文献
9.
A conventional French railway track was instrumented with accelerometers and geophones at three depths: sleeper (surface), interlayer (ITL, z=?0.93 m), and transition layer (TL, z=?1.20 m). A linear variable differential transformer (LVDT) was also used to monitor the displacement at the sleeper level. The recorded data allow the integration method (double for accelerometer and simple for geophone) for displacement determination to be assessed. Several questions need to be addressed prior to the selection of an adequate monitoring system: definition of signal filtering processes, influence on results of the different loading wavelengths, repeatability of measurements, train speed and axle load impact and their ranges of validity for each sensor. It was found that the main frequencies that caused more than 95% of the displacement of the monitored materials are in the low frequency range: <25 Hz for trains running up to 200 km/h. For an intercity train, the low frequencies are normally excited by long wavelengths, for instance, those corresponding to the 1/2 coach distance (λ=13.20 m), the bogies distance (λ=6.3 m), and the axle distance (λ=2.8 m). Comparison between the displacements deduced from the records of accelerometer and geophone and obtained from the records of LVDT shows quite consistent results; the mean displacement amplitudes obtained from accelerometers differ by only 20% from the LVDT records. The train speed does not have a strong effect on the obtained differences between sensors. The embedded sensors also gave consistent displacement results for each analysed depth. Moreover, the displacement amplitudes caused by different axle loads (locomotive or passenger coach) are distinguishable for all sensors at all depths. This validates the integration method used for the displacement determination. 相似文献
10.
A 2.5D finite element approach for predicting ground vibrations generated by vertical track irregularities 总被引：1，自引：0，他引：1
Dynamic responses of track structure and wave propagation in nearby ground vibration become significant when train operates
on high speeds. A train-track-ground dynamic interaction analysis model based on the 2.5D finite element method is developed
for the prediction of ground vibrations due to vertical track irregularities. The one-quarter car model is used to represent
the train as lumped masses connected by springs. The embankment and the underlying ground are modeled by the 2.5D finite element
approach to improve the computation efficiency. The Fourier transform is applied in the direction of train’s movement to express
the wave motion with a wave-number. The one-quarter car model is coupled into the global stiffness matrix describing the track-ground
dynamic system with the displacement compatibility condition at the wheel-rail interface, including the irregularities on
the track surface. Dynamic responses of the track and ground due to train’s moving loads are obtained in the wave-number domain
by solving the governing equation, using a conventional finite element procedure. The amplitude and wavelength are identified
as two major parameters describing track irregularities. The irregularity amplitude has a direct impact on the vertical response
for low-speed trains, both for short wavelength and long wavelength irregularities. Track irregularity with shorter wavelength
can generate stronger track vibration both for low-speed and high-speed cases. For low-speed case, vibrations induced by track
irregularities dominate far field responses. For high-speed case, the wavelength of track irregularities has very little effect
on ground vibration at distances far from track center, and train’s wheel axle weights becomes dominant. 相似文献
11.
Floods result in many problems, which may include damage to cross-river tunnels. The cross-river tunnel, as a new style of transportation, deserves a large amount of attention. In this paper, a large-scale cross-river tunnel model is proposed based on discrete element method (DEM). Micro parameters used in the model are calibrated by proposing a triaxial numerical model. Different in situ strata, high water pressures of normal flood-water levels and random vibration levels induced by running trains are taken into account to evaluate the dynamic characteristics of a high-stress tunnel in deformation and stress analysis. The results show that the upper half of the tunnel, including the concrete lining and the surroundings, is at higher risk than the lower half. Vibration waves transferring into the surroundings undergo an amplification process. The particles of the surroundings at the vault of the tunnel separate and move downward and then reassemble during the dynamic vibrations. The vibration levels, represented by particle accelerations, are lower under flood conditions than those under normal conditions. As train speed increases, the acceleration of the track and particles in the foundation increases, accompanied by a decrease in deformation. 相似文献
12.
With the continuous improvement of the train speed, the dynamic environment of trains turns out to be aerodynamic domination. Solving the aerodynamic problems has become one of the key factors of the high-speed train head design. Given that the aerodynamic drag is a significant factor that restrains train speed and energy conservation, reducing the aerodynamic drag is thus an important consideration of the high-speed train head design. However, the reduction of the aerodynamic drag may increase other aerodynamic forces （moments）, possibly deteriorating the operational safety of the train. The multi-objective optimization design method of the high-speed train head was proposed in this paper, and the aerodynamic drag and load reduction factor were set to be optimization objectives. The automatic multi-objective optimization design of the high-speed train head can be achieved by integrating a series of procedures into the multi-objective optimization algorithm, such as the establishment of 3D parametric model, the aerodynamic mesh generation, the calculation of the flow field around the train, and the vehicle system dynamics. The correlation between the optimization objectives and optimization variables was analyzed to obtain the most important optimization variables, and a further analysis of the nonlinear relationship between the key optimization variables and the optimization objec- tives was obtained. After optimization, the aerodynamic drag of optimized train was reduced by up to 4.15%, and the load re- duction factor was reduced by up to 1.72%. 相似文献
13.
14.
高速铁路站台安全门对乘客的安全性和舒适性起到了很大的作用,但如何合理设置安全门的高度及位置,目前国内尚无相关的理论支持和原始数据的积累.针对以上问题,通过实测高速列车以2种不同的速度通过站台时的风速(影响乘客候车的安全性)和噪声值(影响乘客乘坐舒适性),并将测试数据与相关标准进行对比,提出了安全门的高度应当高于人耳的高度即高于1.5m,对高速列车站台的安全性和舒适性都有较大的改善,为今后高速铁路站台安全门设计提供了参考. 相似文献
15.
When aerodynamic braking works, the braking wings can change the flow field around the train, which may impact on the comfort
and safety. Based on a sliding mesh, the pressure wave and flow field around high-speed trains with aerodynamic braking are
analyzed. By comparing three typical intersection situations, the pressure wave of a high-speed train during braking (with
or without aerodynamic braking) is studied. The analyses indicate that the pressure wave around the high-speed train body
will change while using the aerodynamic braking, causing several pressure pulses on the surface of crossing high-speed trains.
The distances between the pressure pulses are equal to the longitudinal distances of the brake wings, but the magnitudes of
the fluctuations are less than those induced by the head of crossing trains. During the crossing, a train without aerodynamic
braking will not impact the crossing train. 相似文献
16.
通过数学分析建立了EPS数学模型,应用线性PID控制建立了EPS控制模型．采用MATLAB／sim—ulink仿真软件建立了整个EPS的仿真模型．分别选取不同车速对EPS直线型助力特性进行了仿真实验,结果表明：当车速为0km／h时,EPS向汽车转向盘提供的最大助力转矩为20N·M,当车速为40km／h时,助力转矩减小为9N·M,当车速为80km／h时,助力转矩减为最小5N·M．为此,EPS直线型助力特性能贴近驾驶员对不同车速下的转向轻便性与高速行驶下良好路感性的需求． 相似文献
17.
With the development of high-speed train, it is considerably concerned about the aerodynamic characteristics and operation
safety issues of the high-speed train under extreme weather conditions. The aerodynamic performance of a high-speed train
under heavy rain and strong crosswind conditions are modeled using the Eulerian two-phase model in this paper. The impact
of heavy rainfall on train aerodynamics is investigated, coupling heavy rain and a strong crosswind. Results show that the
lift force, side force, and rolling moment of the train increase significantly with wind speed up to 40 m/s under a rainfall
rate of 60 mm/h. when considering the rain and wind conditions. The increases of the lift force, side force, and rolling moment
may deteriorate the train operating safety and cause the train to overturn. A quasi-static stability analysis based on the
moment balance is used to determine the limit safety speed of a train under different rain and wind levels. The results can
provide a frame of reference for the train safe operation under strong rain and crosswind conditions. 相似文献
18.
In order to study the unsteady aerodynamics effects in railway tunnels, the 3D Reynolds average Navier-Stokes equations of a viscous compressible fluid are solved, and the two-equation k-? model is used in the simulation of turbulence, while the dynamic grid technique is employed for moving bodies. We focus on obtaining the changing tendencies of the aerodynamic force of the train and the aerodynamic pressures on the tunnel wall and train surface, and discovering the relationship between the velocity of the train and the intensity of the micro pressure wave at the tunnel exit. It is shown that the amplitudes of the pressure changes in the tunnel and on the train surface are both approximately proportional to the square of the train speed, so are the microwave and the drag of the train. 相似文献
19.
Liang LING Xin-biao XIAO Jia-yang XIONG Li ZHOU Ze-feng WEN Xue-song JIN 《浙江大学学报(A卷英文版)》2014,(12):964-983
研究目的：基于车辆-轨道耦合动力学理论分析方法,建立一种高速列车-轨道三维耦合动力学模型,并明确列车-轨道耦合模型与单节车辆-轨道耦合模型在高速列车-车九道耦合动力学性能分析中的差异。创新要点：建立一种高速列车-轨道三维耦合动力学模型,模型中考虑列车的纵向动力学行为以及车间连接装置对列车中不同车辆动态响应的影响,并基本明确完善的列车-轨道耦合模型在高速列车-轨道耦合动力学性能分析中的重要性。重要结论：单节车辆-轨道耦合模型会过高地估计高速列车在运营过程中的振动响应和动力学性能指标,而完善的列车-轨道耦合动力学模型的计算结果则更加接近实际情况。 相似文献
20.
Installation of rail vibration dampers (rail dampers for short) onto rails between sleepers is one of the measures to control rail noise generation and roughness growth. Amid the rapid expansion of high-speed and underground railway networks in China, many suppliers are actively marketing and promoting their products, often giving confusing information. In this paper, a parametric study is used to investigate the effect of rail dampers on the dynamical behavior of a Chinese high-speed railway track. The Fourier transform-based method developed for analyzing dynamics of a railway track as an infinitely long periodic structure, with or without rail dampers, is applied in the investigation. It is hoped that results in this paper can help develop the understanding of the working mechanism of rail dampers, and provide useful information for product design and application. 相似文献