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Über dieses Buch

This book contains the papers included in the proceedings of the 1st International Workshop on High-speed and Intercity Railways (IWHIR 2011) held in Shenzhen and Hong Kong, China from July 19 to July 22, 2011, which is organized by The Hong Kong Polytechnic University, in collaboration with Southwest Jiaotong University, Beijing Jiaotong University, Dalian Jiaotong University, China Engineering Consultants, Inc., Zhejiang University, and Tsinghua University. Continuing the great initiatives and momentums of the rapid development in high-speed and intercity railways worldwide in recent years, IWHIR 2011 aims at providing a platform for academic scholars and practicing engineers to share knowledge and experience, to promote collaboration, and to strengthen R&D activities related to railway engineering. Engineers, scientists, professors, and students from universities, research institutes, and related industrial companies have been cordially invited to participate in the workshop. These papers have covered a wide range of issues concerning high-speed and intercity railways in the theoretical, numerical, and experimental work pertaining to high-speed and intercity railways. Showcasing diversity and quality, these papers report the state-of-the-art and point to future directions of research and development in this exciting area.

Inhaltsverzeichnis

Frontmatter

A Study on the Generated Characteristics of the Arc Discharge for Contact-Loss of Pantograph

When the train speed reached to 350 km/h or more, the problem of contact-loss became very serious, so the study on the generated characteristics of discharge with contact-loss of pantograph becomes more and more important. In this paper, designed based on a low voltage and high current experimental platform about the contact-loss of the pantograph-catenary which was designed in the laboratory, at any time in the changed cycle of catenary-voltage, spread out more precisely analysis about the phenomenon and the characteristics of arc discharge resulted from the contact-loss of the pantograph-catenary, the waves of catenary voltage, pantograph voltage, pantograph current, arc voltage and arc light intensity were measured. The results showed that: in the processes of contact-loss, the mutation in the waves of the pantograph-catenary voltage and the pantograph current is obvious, but various in degree with the change of contact-loss times; The light intensity and the current of arc changed with the change of off-line times; The changed process of the arc voltage in various contact-loss times are consistent, but the maintenance time of arcing is different and changing regularly.

Wenzheng Liu, Zhongping Yang, Zhaofeng Gong, Weiliang Wang, Huisheng Yang, Ran Liu

A Position Estimation Method Based on Modified Integrator of PMSM Sensorless Control for High-Speed Vehicles

In the high-speed traction permanent magnet synchronous motor (PMSM) drive system, control methods without position and speed sensors are adopted because of occupying smaller space, lower cost, higher reliability and less sensitivity to the environment which is more suitable for motors using in traction vehicles. According to the stator voltage and measured current, the stator flux is integrating from the difference value of the voltage, where back-EMF can be calculated and rotor position can be estimated. Based on the estimating method of integrating back-EMF, this paper proposes a modified integrator to solve the problems produced by the pure integrator, which brings up DC offset to estimating motor flux. Simulation and experiment results show that this integrator can accurately estimate both the magnitude and the phase angle of the motor flux, including the speed of PMSM. Besides, the perfomance of the integrator shows that it has good dynamic and steady characteristics.

Qian Yuan, Zhongping Yang, Ling Cui, Taiyuan Hu, Fei Lin

The Influence of Different Cross-Section Shapes of Train Body on Aerodynamic Performance

In this paper, the influence of different cross-section shapes of train body on aerodynamic performance has been investigated by numerical simulations. Computational fluid dynamics (CFD) is used with the second-order finite volume method with SST k-omega turbulence model. The results indicate that the aerodynamic performance is strongly affected by different cross-section shapes of train body, such as cross-sectional area, width-to-height ratio of cross-section, cross-section with straight or curved sides, etc.. Firstly, the drag coefficient and the overturning moment increase as the sides of cross-section become more curved. Secondly, the drag coefficient and the overturning moment are reduced as the width-to-height ratio of the cross-section is increased when the cross-sectional area is kept as a constant. Finally, air pressure pulse produced by two trains passing by in tunnel is approximately proportional to the cross-sectional area in a certain range and is independent to the cross-section shapes. Numerical results can be used for aerodynamic shape design of high speed trains.

C. H. Liu, Dilong Guo, Shuanbao Yao, Guowei Yang

Investigation of Aerodynamic Performance of High-Speed Train by Detached Eddy Simulation

The detached eddy simulation (DES) is employed to study the flows around the high speed train at speed of 500km/h. Its object is to evaluate the aerodynamic performance. As we know, for high speed trains at speeds bigger than 250 km/h, most (about 75–80%) of the total resistance is caused by aerodynamic drag. Hence, it is important to accurately predict the aerodynamic drag for the designer of new shape of train. To achieve this goal, one of the challenge problems is to capture the massively separations in the wake region which are rarely explored in the literature. To further simplified the problem, the study is only applied to the simplified modelling train which does not include items like bogies, pantographs etc. The results show that DES can capture the separation as well as the small scales of eddies in the wake region.

Hongwei Zheng, Guowei Yang

The Influence of Pantograph Aerodynamic Characteristics Caused by Its Shroud

The current collection performance of pantograph plays an important role in safe operation of high-speed train. Research shows that pantograph aerodynamic characteristics have a great influence on the current collection of pantograph. It’s an efficient method to install a suitable pantograph shroud to improve the pantograph aerodynamic performance. In this paper, for the real pantograph systems used on CRH380A and CRH380B, the influence of unsteady aerodynamic characteristics caused by different types of pantograph shrouds with a running speed of 350km/h has been studied with detached eddy simulation method. The results show that the wake field caused by pantograph has salient unsteady characteristics. Different designs of pantograph shroud largely affect the pantograph wake field and the lift, drag and side forces of the pantograph slide. Compared to pantograph without shroud, the pantograph with shroud owns a more complex wake field. Besides, the strength and shedding frequency of the detached eddy vary a lot. This phenomenon becomes more serious in the cross- wind condition. The drag of pantograph slide increases about 12.8% and the lift reduces about 13.5% thanks to the pantograph shroud in CRH380A, while the drag reduces about 7.4% and the lift increases about 100% due to the pantograph shroud used on CRH380B. In the end, the author gives the pantograph shroud aerodynamic optimization recommendations based on the research results.

Shuanbao Yao, Dilong Guo, Guowei Yang

Railway Track Allocation - Simulation, Aggregation, and Optimization

Today the railway timetabling process and the track allocation is one of the most challenging problems to solve by a railway company. Especially due to the deregulation of the transport market in the recent years several suppliers of railway traffic have entered the market in Europe. This leads to more potential conflicts between trains caused by an increasing demand of train paths. Planning and operating railway transportation systems is extremely hard due to the combinatorial complexity of the underlying discrete optimization problems, the technical intricacies, and the immense size of the problem instances. In order to make best use of the infrastructure and to ensure economic operation, efficient planning of the railway operation is indispensable. Mathematical optimization models and algorithms can help to automatize and tackle these challenges. Our contribution in this paper is to present a renewed planning process due to the liberalization in Europe and an associated concept for track allocation, which consists of three important parts, simulation, aggregation, and optimization. Furthermore, we present results of our general framework for real world data.

Ralf Borndörfer, Thomas Schlechte, Elmar Swarat

Experimental Modal Analysis of High-Speed EMU Carbody Structure

Modal is the natural characteristic of structural vibration, each mode has a specific frequencies, damping and modal shape. Modal parameters reflect the dynamic properties of the structure. The dynamic characteristics of car-body structure play an important role to the stability and comfort of the High-speed EMU (Electric Multiple Unit). Experimental Modal Analysis (EMA) is the common method to study the structural dynamic characteristics. This paper adopts the EMA technology to analyse the high-speed EMU car-body structure. The car-body structure is supported by coil springs, which simulates the operational condition. The system uses two electromagnetic exciters to produce the excitation force, and the burst random signal is used. Two piezoelectric transducer are applied to measure the force, 285 piezoelectric acceleration sensors are used to pick up the vibration response, and the LMS-SCADA III is used to acquire data. Based on multiple-input multiple-output (MIMO) method, modal testing is performed. The PolyMAX method is utilised for extracting the modal parameters: frequencies, damping and modal shape. The vibration characteristics of the car-body structure have been further understood through the modal parameters, which also can be used for the vibration and noise reduction design.

Yanchuang Ding, Qiang Li, Zhencheng Chang, Wenzhong Zhao

An New Approach for Acceleration of Train Model with Compressed Air

In order to accelerate a heavy train model with a large dimension to a velocity higher than 500 km/hour for the moving model test, the compressed air is utilized to drive the model indirectly. The gas from an airgun impels a piston in the accelerating tube for a uniformly acceleration. The piston connects a driving device through a rope and the device promotes or pulls the train model for a desired velocity. The deceleration of the train model and the driving device are all realized by the friction between the brake plates and the rubber blocks. The principium experiment results reveal that the initial pressure of the airgun is linearly proportional to the kinetic energy of the model where the moving assembly with a weight more than 10 kg has been accelerated to 420 km/hour in an accelerating distance of 20m.

Q. S. Yang, J. H. Song, Guowei Yang

Automated, Passenger Time Optimal, Robust Timetabling, Using Integer Programming

To design an optimal passenger train timetable one should choose a quality criterium or a combination of criteria. We consider the main quality criterium from a passenger perspective: journey time. This means that the expected time all passengers will spend when our timetable is put in practice is minimal, even taking into account typical train delays. From a train operator or rail infrastructure management company perspective, there are further concerns too, like the number of train units that has to take part in this schedule, their frequency, the number of drivers and other crew members. These factors are all related to cost to maintain the schedule but are here considered secondary and indeed, are here kept constant. We consider only the passenger criterium here. We analytically derive total stochastic expected passenger time as a closed formula, linearize it and use it as a goal function for optimizing the schedule using a mixed integer linear programming model. We applied this to all 224 current Belgian train relations, passing 550 train stations and calculated an optimal schedule in 3 hours. We believe this mathematically optimal approach is unique, in its detailed model of expected, stochastic passenger time, in its scale of implementation and in its use of actual current data from practice.

P. H. A. Sels, T. Dewilde, P. Vansteenwegen, D. Cattrysse

Strategy Research of High-Speed Railway Promoting Liaoning Regional Economy Development

In recent years, high-speed railways of our country have gained world-beating achievements. As a modern tool of transportation, from the day of its birth, the high-speed railways relies on its powerful vitality have motivated countries, regions and cities social economical development, especially great function in process of motivating regional economy integration and urbanization. Till now, building high-speed railways has become the common view of governments. Predictably, railway transportation of 21th century will show integrated development of high-speed railway, the age of world-wide high-speed net work has come. Base on empirical research, this article describes development condition of both domestic and foreign high-speed railway; combine with fact of China, from experiencemental point of view to discuss function mechanism high-speed railway improving regional economic development; using Shenyang Raiway Bureau high-speed railway construction affect on Liaoning regional economical radiation and promotion as example for empirical research, summarize the influence of high-speed railway towards Liaoning economical development; and use the experience in high-speed railway construction of other developed countries for reference, put forward development strategies of high-speed railway promoting Liaoning regional economical construction, in order to fulfill more achievement in process of Liaoning regional economic development by high-way rail construction.

Shaofu Sun

A Numerical Study on Aerodynamic Noise Sources of High-Speed Train

Firstly, in order to investigate the noise generation mechanisms of the pantograph, the key source in aerodynamic noise generation, the basic models of a circular cylinder and a series of rectangular cylinders were numerical studied respectively and compared in detail. Secondly, the aerodynamic noise sources of a high-speed train were visualized, through the numerical simulation of a real three-coach high-speed train. Finally, the far-field noise levels are given in 350 km/h and 400 km/h. Based on the results, flow and noise source generation mechanisms on the high-speed train were revealed.

Yan Yang, Guowei Yang

Fuzzy Grey Fault Tree Analysis on Wagon Bogie Reliability

The method of combining grey relational analysis with fuzzy membership function is presented to solve the probability of failure modes. Fuzzy grey fault tree model is proposed. The fuzzy relational degree is calculated and wagon bogie weak links are found. The disadvantages in various multi-parameter dimension and magnitude differences are overcome. Example analysis shows that the model is accurate and reasonable.

Yonghua Li, H. T. Liu, Yuehua Gao, Bingzhi Chen, G. G. Wang

Conceptual Design of Prestressed Structures

Prestressing is an important technique in the railway engineering especially for the railway bridges. It is necessary to develop some design method such as the topology optimization technique for the prestressed structures from the primary stage. However, the topology optimization of prestressed structures is seldom investigated in past. The aim of this paper is to establish a topology optimization procedure for prestressed structures. Two loading-steps are constructed two describe the whole prestressing procedure. Moreover, a topology optimization scheme that has the objective the minimum deflection and the constraint of the permitted material volume fraction as well as the pre-force level is proposed. Some typical example is performed to test the optimization model. The results indicate that the optimal prestressed structures are quite different from those of ordinary structures.

W. Z. Su

Numerical Research on Temperature Field of Equipment Compartment of 350km/h EMU Running on Open Line

Higher speed of train and the change of environment temperature could have a great impact on normal operation of equipments in the equipment compartment. By using continuity equation, Reynolds-Averaged Navier-Stokes equation, and RNG k-

ε

turbulence model equation, the temperature field in the equipment compartment is simulated numerically when EMU is running at speed of 350km/h on open line. For the heating dissipation of the traction convertor and the transformer in the equipment compartment is higher, this paper creates a 3-D model of interior and exterior flow field of high speed EMU consisting of 5 carriages running at the speed of 350km/h on open line. The temperature distribution of the inner equipment compartments of the model is researched numerically and the detailed information of temperature distribution in each equipment compartment is obtained when the environment temperature is 40℃, 35℃, 30℃, 20℃, 10℃, 0℃, -25℃, -40℃ respectively. The numerical calculation result shows that when the temperature is 40℃, the surface temperature distribution of the traction convertor in the first carriage is about 41.2~45.5℃, the maximum temperature is 52.5℃. The surface temperature distribution of the transformer in the second carriage is about 43~48.1℃, the maximum temperature is 65.4℃. The surface temperature distribution of the traction convertor in the third carriage is about 43.0~46.7℃, the maximum temperature is 68.7℃. Besides, the surface temperature distribution of these three equipments is same in different environment temperatures. The calculation results can give a strong technical support especially for designing the grilles of numbers and location on side skirts, and the layout of the equipments in the equipment compartments of the high-speed EMU.

Dongping Wang, Guangping Xu, Feng Liu, Xiaozhen Mi

Aerodynamic Numerical Simulation for EMU Passing Each Other in Tunnel

Transient pressure variation generated by two trains passing through a tunnel has great influence on train safety and passenger comfort. Therefore, research on this area is particularly important. The model of 350km / h EMU of three cars passing each other through a 300m tunnel with constant velocity was built, based on three-dimensional unsteady Navier-Stokes equation of compressible viscous fluid and RNG

κ

ε

turbulent model. This process was calculated numerically by means of finite volume method, pressure and aerodynamic forces of train, while pressure variation of tunnel was studied in this article. The results show that pressure variation of different points is similar for the identical side of the train, and pressure variation of the middle tunnel is most violent when the EMU are passing each other here; compared with single one. The pressure amplitude of train crossing each other in a tunnel is twice more, head of the train get the highest value with 177.3% bigger, while the pressure amplitude of the middle tunnel is twice as single one approximately; besides, the air resistance and side force are larger, while the lift force is minor relatively, the max drag coefficient is 1.340, the max lateral force coefficient is 0.567, and the max negative lift coefficient is -0.190; in terms of different cars, the middle one comes in for the smallest force of all, while drag force amplitude of the head and middle car are 136.3%, 20.7% larger than the middle one separately, lift force amplitude are 76.1%, 79.5% larger and lateral force amplitude are 38.8%, 24.2% larger separately.

Dongping Wang, Weipeng Li, Wenzhong Zhao, Han Han

Influence of Pile Cap Effect in Piled Embankment Supporting High-Speed Railway

Based on the field test, the development of pressure and settlement above pile cap and soil surface are obtained. Test results indicate that both relative settlement and pressure ratio vary with the filling before the height of embankment is less than 0.9 m, after which the relative settlement tends to be stationary while pressure ratio keeps rising till the end of filling and becomes steady quickly in standing period. Furthermore, the numerical simulation is adopted to analyse the influence of pile cap coverage ratio on settlement and pressure distribution in the single pile processing area. Results show that enlarging the diameter of pile cap can improve the settlement stability of soil between piles remarkably, while narrowing pile distance can reduce the settlement of soil effectively.

Hongyun Chen, Jianlin Ma, Xiaogang Qin

Application of Strut-and-Tie Method for Railway Reinforced Concrete Structure

In some foreign countries, the strut-and-tie method (STM) is an effective path to solve D-regions problem. Because of better mechanical concept and higher precision compared with traditional design method, the STM is extensively applied to design and calculate the regions where the strain distribution is nonlinear (internationally called D-regions). In this paper, on the basis of concept and principle of the STM, the requirements, procedures and aspects demanding attention of developing strut-and-tie models are reviewed. In addition, uniqueness of these models is also discussed. At last, two designing examples are studied to demonstrate the application of the STM in the railway reinforced concrete structure.

Jichao Zhu, Jinxin Gong

Hybrid Prediction Model for High-Speed Railway Embankment Settlement Using Grey Artificial Neural Network

Embankment settlement prediction and control is one of the most critical problems for constructing and maintaining the High-speed railway (HSR). The grey model is one of the popular methods used for predicting embankment settlement, because it is of easy-to-use and low computer load. However, it needs many observations and more suit for short-term prediction. The artificial neural network has been widely used in prediction system in many other fields, and it is of robustness and self-adaptive. In this paper, these two methods are combined to give a new Hybrid prediction model to improve the performance and precision of settlement prediction model. The experiments based on real data sets validate the proposed method.

T. G. Zhang, Z. B. Hu, C. F. Yang, Y. Liu

Shape Optimization of High-Speed Train with the Speed of 500kph

With the train speed becoming faster and faster, the aerodynamic drag turns to be one of the essential factor that restricts the train speed ascent. However, no public literature, abroad or abroad, has dealt with the flow field and aerodynamic performance of the train with the speed reaching 500km per hour. In this paper, an optimization study is carried out to reduce the aerodynamic drag of the high speed train (HST). First of all, a grid-based method is presented to parameterize the head shape of the HST, key variables are obtained by sensitivity analysis. Next, a response surface is constructed based on computational fluid dynamics (CFD) analysis to approximate the relationship of the drag and design variables at 500KPH. Finally, the genetic algorithm is used to optimize the head shape of the HST.

K. Cui, X. P. Wang, S. C. Hu, T. Y. Gao, Guowei Yang

Optimum Structural Designs for an Equipment Cabin under High-Speed Train Considering Aerodynamic Load

Equipment cabin under a high-speed train is a kind of structure for protecting the suspension equipments and reducing the air resistance when a train runs. With the increase in speed of a train, the issues related to safety like the structural strength, structural stiffness, weld fatigue etc. must be considered in the design of the high-speed trains. At the same time, the aerodynamic action caused by high speed must be considered. In this paper, optimum structural designs are implemented for a typical equipment cabin where two Doppler radar velocimeters hang. First, the topology optimization for the frame ribs is implemented with the stress and displacement constraints. After the topology optimization, the detailed size optimization is carried out to minimize the total weight. To obtain all the responses, finite element model of the equipment cabin is analyzed under aerodynamic and acceleration loads. The optimization results show the weight is reduced about 8%.

Yuehua Gao, Wenzhong Zhao, Yonghua Li, Bingzhi Chen

Bridge Design Concept and Innovation of Chengdu-Dujiangyan Intercity Railway-Post Wenchuan Earthquake Reconstruction Project in Sichuan, China

Chengdu-Dujiangyan Railway is the first major post-earthquake reconstruction project after wenchuan earthquake. The area along the railway is densely-populated and economically-developed Chengdu Plain, especially Mount. Qiangcheng and Dujiangyan are world-famous tourist attractions. The bridge is designed under the guidance of overall landscape planning of the whole line. The single-box single-cell section and inclined web with a big angle of inclination is used for simply-supported box beam. The shield and noise barrier are designed together with outline of beam body as a whole, which may make bridge aesthetical in appearance and meet the requirements of technical standards in dynamical performance and load bearing capacity of the structure. On the full consideration of the characteristics of the railway, the seedling-shaped piers are adopted, which have a profound meaning, and also a landscape effect for effectively taking into account both high pier and low pier. The continuous beam bridge is designed according to the principle of smooth transition with adjacent simply-supported beams. The movable bearing for main pier is the pot rubber bearing with damper. In the event of earthquake, the dampers will be locked, which make piers with movable bearing and piers with fixed bearing together bear the longitudinal horizontal force. For the wider turnout continuous beam the partitioning width structure design method is used to reduce the influence due to transverse deformation. For overpass highway intersection with a small angle the frame pier is used and the slotting method on the column body is used to increase the vertical visual effect. The setting of bearing on the top of partial columns for long bent cap frame pier in the elevated station can reduce effectively the temperature effect. The noise barrier is designed with the shield matching on the bridge. The steel plate is embedded on the top of shield as the foundation post for noise barrier or as reservation of the foundation condition of post for noise barrier.

Lie Chen, Ying Zhu

Research on Computer Simulation Technology for Track System Optimization in Urban Rail Design

With the rapid development of urban rail transit, the design of track system should take into account of the safety, ride quality of train, durability of track, maintain of environmental friendship simultaneously. Conventional design methods usually focus on detailed type selection of rail, fasteners, turnouts, track bed, and vibration mitigation tracks. Experiences revealed that the conventional methods were deficient in enhancing the combinational dynamic property of coupled train-track system. Based upon the theory of vehicle-track coupling dynamics, an advanced computer simulation technology was proposed. The paper systematically and briefly presents the application of the method that be used to study the effects induced by geometric and stiffness irregularity, transition sections, rail corrugation, and dynamic parameters of vibration mitigation track to the train-track system.

Zhenxing He, Shichun Wang, Shuzhen Wang

Modal Parameter Identification of Linear Time Invariant System under Non-stationary Ambient Excitation

In this paper, a new modal parameters identification method is presented based on NExT (natural excitation technique) and the response data of the structure under non-stationary ambient excitation the white noise excitation assumption for NExT is extended to a MA (q) model assumption to establish an extended NExT method. Then the assumption that the non-stationary excitation is composed of a (d-1)-th order polynomial and a MA(q) model is proposed. Taking d-th order difference of the non-stationary excitation yields a MA(q+d) model, which satisfies the assumption of the extended NExT method mentioned above. Thus, the extended NExT method can be used in the condition of non-stationary excitation. In order to reduce the error of difference calculation during identification implementation, the difference computation is performed in frequency-domain instead of time-domain. The identification results from the proposed method are compared with the standard NExT for a three DOFs (degrees of freedom) vibration system and the finite element (FE) model of Longtanhe Bridge. The results show that the method proposed in this paper can obtain better modal parameters of the system under non-stationary ambient excitation than the standard NExT.

Lukai Xiang, Qiuhai Lu

Dynamic Analysis of the Vehicle-Track-Bridge Interaction Using Vector Form Intrinsic Element Method

This research develops a three-dimensional computation code to analyze the vehicle-track-bridge interaction behaviors. The main object of this research is to apply the vector form intrinsic finite element (VFIFE, V-5) method to calculate the nonlinear dynamic response of bridge under the vehicle. The VFIFE method is used to simulate the vehicle, the track and the bridge. The VFIFE method can compute the motion of rigid body and deformable body for the vehicle. It can’t require any iteration or any parameters during computation for solving the problems. In addition, using frame elements to model the shape of the vehicle is called vehicle model using frame elements (VMFE). The VMFE is used to simulate motion of a derailed carriage. In this paper, the VFIFE method provided an effective numerical method for the vehicle-track-bridge interaction behaviors.

J. Y. Shih, C. Y. Wang, R. Z. Wang

Railway Dynamometric Wheelsets: A Comparison of Existing Solutions and a Proposal for the Reduction of Measurement Errors

Currently, the testing for the acceptance of running characteristics of railway vehicles in Europe is ruled by EN-14363 which is derived in essential parts from UIC 518. This standard is based on present state of the art which is generally applicable for test procedures and the evaluation of stationary and ‘ontrack’ tests. It defines testing scenarios, analysis conditions and experimental measurements, and proposes limiting values for a number of different parameters mainly associated with vehicle safety and ride quality. Variables to be measured are specified for each method. The method referred to as “normal”, which is applied to the cases of the highest level of criticality (high speed and/or high axle loading) requires the measurement of forces transmitted through wheel-rail contact at several wheelsets of the vehicle.

Consequently, the accurate experimental measurement of wheel-rail forces is vital both for railway vehicle acceptance processes and for fundamental research in the field of vehicle-track interaction. Wheel-rail forces are measured by so-called “dynamometric wheelsets”, i.e. wheelsets in which multiple sensors are arranged in predetermined positions.

During the last decades, several measurement methods have been proposed. When analysing the theoretical background of the different methods it can be seen that their accuracy can vary depending on several factors such as: gyroscopic effects, shape of the wheel web, position of the wheel rail contact, vehicle speed, etc.

Generally, under extreme conditions wheel/track forces tend to be very close to the limits established in the standard, such that measurement accuracy of forces transmitted through wheel-rail contact is a highly key factor. However, the standard does not propose any measurement method, or requirements for the precision of such measurements. This results in serious uncertainties in the acceptance process. This work proposes a variety of solutions that provide an improvement over existing solutions, laying the starting basis for the development of new dynamometric wheelsets that meet current requirements for accuracy.

E. Gómez, A. Alonso, J. G. Giménez, J. Vinolas

The Research on Fatigue Damage due to Tunnel Aerodymical Load Acting on the Body of High-Speed Train

When the EMU running through the tunnel with high speed, especially for EMU of Wuhan-Guangzhou line. In addition to mechanical load, the aerodynamic loads of the body fatigue damage should not be ignored, and it will be enough ability against fatigue or not is a very important issue. In this paper, a new method of Fatigue life assessment takes into account aerodynamic loads was proposed. The contents of this paper are introduce the parallel computing platform based on aerodynamics simulation tunnel firstly, then calculation the structure dynamic stress response based on fluid - solid coupled was discussed. And then Master S-N Curve Method Based on Fatigue Damage and how to define and obtain the structural stress that could present the stress concentration on the weld, and how to define and obtain the equivalent structural stress that could be used to calculate the fatigue life on the weld are presented. Finally two engineering examples, including how to create such calculating mode are presented in this paper to testify its special application value for against fatigue design in High Speed Train.

Y. D. Wang, X. Y. Cai, Wenzhong Zhao, Bingzhi Chen

Aerodynamic Design on China New High-Speed Trains

The high-speed trains have very complex running environments, which contain single-train running in open air, two-trains passing by in open air, single-train running in tunnel and two-trains passing by in tunnel. As the environment wind appears, cross-wind effect must be considered. Aerodynamic design of high-speed trains mainly aims at the drag, lift, moment, impulse pressure waves, aerodynamic noise etc at typical running conditions. In the paper, the aerodynamic design processes of CRH380A and 380B are introduced and the aerodynamic performances of different designs are emphatically analyzed and compared. Wind tunnel experiments and running tests indicate that the new generation of high-speed trains holds excellent aerodynamic performances.

Guowei Yang

Research on Influence of the Type of Cross Wind Field on the Aerodynamic Performance of a High-Speed Train

Characteristic of cross wind field, such as uniform wind and lower atmospheric boundary layer wind, have directly influence on the operation safety of high-speed train which running in cross wind environment. In order to accurately assess its effect on the train running in flat land, flow field and aerodynamic characteristics of the high speed train running at 350 km/h under different wind directions in these two types of Wind field mentioned above were simulated numerically and analyzed. The results show that, for a train running in the condition of the crosswind in flat land, aerodynamic lift, lateral force and overturning moment acting on the train increased rapidly with the wind direction angle increasing; when the train running through the lower atmospheric boundary layer, compared to an uniform wind filed, the pressure difference of the train at top, bottom and two sides were less, lateral force and overturning moment were also less, and aerodynamic lift had some uncertainty when the wind direction angle increased. Using the uniform wind for the operation safety evaluation of high-speed train which running in cross wind environment will overestimate risks the cross wind on the train operation safety, make the safety of the train too low to limit speed, thus affect the normal operation and the traffic efficiency. The lower atmospheric boundary layer wind was suggested to be used for the evaluation of the aerodynamic performance of a train.

Y. H. Xi, J. Mao, Guowei Yang, Y. Fang

Magnetoelectric Smart Current Sensors for Wireless Condition Monitoring of Train Traction Systems

Condition monitoring of train traction systems has become increasing crucial to train operators in terms of safety, reliability and availability. Current signatures governed by electric motor drives of train traction systems are physically valuable to represent the operating conditions of the train traction systems. However, the long train length, tough and complex system connections, critical measuring locations, high-voltage and heavy-current environment, etc. always impose great difficulties when installing wired condition monitors involving active current sensors (e.g. current transformers, Hall sensors, Rogowski coils, etc.) which are often accompanied with the need of power supplies and signal conditioners. In view of this, we have developed power supply-free, signal conditioner-free, surface mount-type magnetoelectric smart current sensors and integrated them with a 4-channel, 2.4 GHz wireless communication (transmitter and receiver) unit. Four pairs of sensors and wireless transmitters have been installed on electric cables associated with the four electric motor drives situated underneath the 2nd, 5th, 8th and 11th cabins of a 12-cabin mainline train running between Hong Kong and Shenzhen, China. A 4-channel wireless receiver has been housed in the driver cab to provide real-time, wireless monitoring of the current signatures of the four electric motor drives. In this paper, the development of the sensors and wireless communication unit is described, and the field installation and test results are presented.

C. M. Leung, S. Y. Zhang, S. W. Or, S. L. Ho, K. Y. Lee

Development of Piezoelectric Transformer -Coupled Solid State Relay for Electrical Circuit Control in Railway Systems

A solid state relay (SSR) is an electrical ON-OFF control device through which electrical power to the load is switched either ON or OFF by a small control signal. The device serves the same function as a classical electromechanical relay but carries no moving parts so that it has faster switching time, longer lifetime, higher reliability, no sparking, lower electrical noise, no mechanical noise, stronger tolerance to mechanical shock and vibration, smaller size, lighter weight, etc. Photo-coupled SSR (PcSSR) is regarded as the most popular type of SSR nowadays. However, the susceptibility of PcSSR to lightening or power surge often requires specific protection to ensure its normal function and performance, especially for railway systems. Recently, we have developed a novel type of SSR, called piezoelectric transformer-coupled SSR (PTcSSR), by using the high input-output isolation property of piezoelectric transformer for coupling between the input small-signal control circuit and the output load circuit. In this paper, we report the design, fabrication and performance of a 12 V dc input, 220 V, 2 A, 50 Hz ac output PTcSSR, and compare the measured performance data with those of a commercial PcSSR used for electrical circuit control in modern railway systems.

W. Kuang, S. W. Or, C. M. Leung, S. L. Ho

On-Track Load Spectrum Test Study of Motor Bogie Frame of High-Speed Train

Taking the bogie frame of high-speed train for object, the axle box spring and arm are calibrated into load sensors. The vertical load and lateral load time history of the bogie before and after the wheel profiling are obtained through the track test on Wuhan-Guangzhou line (WuGuang Line). The load characteristics are compared to evaluate the effect of the wheel profiling under the typical service cases such as straight line and curve passing. The loads of bogie frame were basically divided into four main basic load series such as sink-floating, side-rolling, torsion and lateral load. And the load spectra are compiled and the spectrum comparison is carried out between before and after wheel profiling.

W. J. Wang, S. G. Sun, S. L. Liang, S. B. Wang

Magnesium Alloys - New Materials for High-Speed Train with Reduced Vibration and Noise

Due to low density and higher specific strength and rigidity than aluminium alloys and steels, magnesium alloys could be used in railway vehicles with less weight. Moreover, magnesium alloys have better capacity of vibration reduction than aluminium alloys and steels. In this report the previous work was shown, such as Mg honeycomb panels, Mg extruded profiles and their final product as berth, ventilating windows. The application of Mg alloys could produce weight, vibration and noise reduction, and improve running safety and higher energy efficiency for high-speed train.

Gaofeng Quan, Ruichun Li, Xiu Gu, Zhaoming Liu

Design and Implementation of Data Generation for CBTC

For the low efficiency of data generation in CBTC(Communication Based Train Control), this paper proposes a data generation method based on ObjectARX. On the basis of CAD graph data structure, and the data elements and data structure in CBTC, we design and realize the method of lane data generation for CBTC by means of C# program language and ObjectARX which is a secondary development tool of AutoCAD. Finally, with the lane data of Yizhuang Line of Beijing, it is proved that the method is feasible and can improve the efficiency of data generation and the accuracy of data.

Qiuli Dong, Youneng Huang, Wei Wang

Vibration Measurement on Viaduact of Taiwan High Speed Railway

There were 13 standard spans of variant span length and pier height tested at early stage of Taiwan High Speed Railway’s operation. The test was aimed to verify the actual dynamic responses meeting the design code, and to establish the initial values of bridge structure dynamic behaviors. In this test, triaxial accelerometers and triaxial velocimeters were mounted on box girder to measure the structure vibration of prior, during and after train passing, which refers to ambient vibration, force vibration and free vibration, respectively. More than one hundred train passing events have been recorded. The measurements were utilized to extract the distribution of natural frequency, dynamic response comparing to different train speeds and different span lengths.

C. S. Chen, M. H. Chen, C. Y. Wang

Ontology-Based Approach for Automated Quality Compliance Checking against Regulation in Metro Construction Project

A metro construction project has to meet the requirements of related standards and regulations. This is usually achieved through compliance checking. However, nowadays, as a manual and highly labour-intensive task, the construction quality compliance checking leads to excessive work for inspectors. Therefore, this paper proposes an ontological methodology to support automatic construction quality compliance checking, in which knowledge of regulation constraints is formalized in OWL (Web Ontology Language) and SWRL (Semantic Web Rule Language) and the construction quality inspection data are represented as instances of OWL ontology. The proposed methodology is illustrated with a regulation example taken from “Acceptance Codes for Construction Quality of Building Foundation (GB50202-2002)”.

B. T. Zhong, H. B. Luo, Y. Z. Hu, J. Sun

The One-Dimensional Unsteady Flow Prediction Method and Applications on the Pressure Waves Generated by High-Speed Trains Passing through a Tunnel

Whenhigh-speed trains pass through tunnels, large pressure fluctuations are produced and propagated through the tunnel as waves. These pressure waves affect the comfort of passengers. A number of one-dimensional methods for predicting the pressure waves have been developed and realistic results have been obtained in about forty years. The numerical method is introduced based on one-dimensional, unsteady, compressible, non-homentropic flow model and method of characteristics in the paper. The different applications of this numerical method are presented for the principal features of the flow in a high-speed railway tunnel. The application examples include a train passing through a tunnel and two trains passing each other in a tunnel. The examples have been carried out under the different conditions of the tunnel without or with airshafts, cross-passages, and perforated wall in tunnel.

Y. G. Mei, C. H. Zhou

Health Monitoring and Disease Prevention of Curved Tracks

The curved track is an important but weak part of the railway line. Diseases of the curved track have long been a prominent problem, not only significantly reduce the life but also bring a great threat to the safety of the railway. Maintenance of the curved track accounts for a large proportion of the maintenance of the entire line. So far, no effective measures could prevent the occurrence of the diseases. Measures commonly used can only reduce the incidence of such diseases. This paper describes the characteristics of the curved track and analyzes the types of curved track diseases and the influence factors of each type of disease. A health monitoring system is then introduced for the curved track. Feasible and effective prevention measures are discussed to reduce the incidence of curved track diseases.

Y. F. Duan, Q. B. Ni, Ying Zhu, B. Q. Gao

Wireless Sensor Networks for Earthquake Early Warning Systems of Railway Lines

Earthquake early warning system (EEW) is of huge interest as the general public is less and less willing to accept that earthquake damage to lives and properties is a fate to bear. Carrying high social and commercial value, high speed railway lines stand at the weakness point for the public to endure such fate if earthquake happens. There are many earthquake early warning systems. The key of the EEW is an

accurate

and

timely

report of earthquake warning under such constraints as geographical and geological prediction limitation, communication constraints, fault tolerance; to name but a few.

Wireless sensor network (WSN) is used in many domains due to its advantage in cost, simple maintenance, robustness, etc. There are calls to use WSN for EEW in recent years. In this paper, we first present a modular designed WSN framework for EEW. In this framework, we study two bottlenecks of applying WSN to EEW. First, we study the locations that the sensors should be placed (or the sensor density), so as to achieve a timely warning report and system efficiency. We observe that wireless communication is faster than the destructive S-wave of the earthquake. Therefore, a trade-off can be made so that the number of the sensors to be deployed or maintained can be significantly reduced. Intrinsically, the faster P-wave of the earthquake should first hit at least one sensor which can gather, compute and transmit this information to the damage prone point, before the S-wave arrives. Second, we study a deadline driven strategy for WSN to reduce false alarms. In this case, the WSN of EEW and the WSN of the railway line health monitoring system will work together. Since the sensors of the railway line health monitoring system of the railway lines are densely deployed, there will be a great number of reports generated. An early aggregation of the information is needed to localize and evaluate the earthquake range and impact. False alarms should be filtered out.

These problems are intrinsic and cannot be improved by engineering advances. A joint foundational understanding of the communication limitation, complexity reduction of the computing systems, and earthquake knowledge is required. We believe that this work can serve as a first step before the development of a practical EEW system.

Dan Wang, Yiqing Ni

Predicting the Vehicle Induced Building Vibration by Multi-source Fuzzy Dynamic Analysis

The structure vibration induced by building base dynamic excitation often has harmful effect to the comfort of residents or the applicability of precise instrument inside. So, predicting the proposed building vibration is necessary. This paper presents a new method based on multi-source fuzzy finite element dynamic analysis to predict the building vibration caused by traffic loads of vehicles. The uncertain parameters of the dynamic function are the fuzzy sources including structural mass, stiffness, damping matrix and the excitation magnitude on the structure base. The fuzzy dynamic characteristics and frequency response function with multi-source fuzzy number are discussed. Finally, the example with fuzzy excitation on structure base is given. Some key steps of this method are contained: 1) the acquisition of the vibration acceleration data of the ground excitation, 2) the analysis of the one-third octave band power spectrum density of the test data, 3) the construction the fuzzy source membership functions of favorite center frequencies of the one-third octave band, 4) the construction of fuzzy finite element dynamic model of the building which residents complaining. 5) the analysis of the fuzzy membership function of finite element dynamic model response, 6) the overall weighted root-mean-square acceleration value in

α

-sublevel of fuzzy number by ISO2631-1,2 standard.

Baisheng Wang, Yinwu Yang, Weiqiu Chen

Failure Detection on Train Bogie Frames Using Guided Waves and an Image-Based Approach

Welded tubular steel structures (WTSS) are widely used in bogie frames of train, which usually play vital roles in the whole framework. Structural Health Monitoring (SHM) in terms of ultrasonic guided waves (UGWs)-based technology on such kind of structures deserves in-depth investigation. In this study, propagation behavior of UGWs in a WTSS, which is a real size model for a train bogie frame segment, was investigated using both finite element method (FEM) and experimental analysis for the purpose of damage evaluation. A sensor network made up of piezoelectric wafers was employed to generate UGWs and collect response signals. Excitations at chosen frequencies were applied to the active PZT transducers with the aim of getting enough signals for study. An imaging approach based on a signal feature named “time of maximal difference” (ToMD) and the subsequent concept “damage presence probability” (DPP) was developed and then utilized to estimate the presences and locations of multiple welding damages in welding zones. In virtual of a dual-level data fusion procedure, visualized and numerical results for damage evaluation were obtained and analyzed. It’s indicated that the recommended approach is effective and accurate in evaluating damage presence and location in the given conditions. Subsequently, two fatigue cracks, as common failures in WTSS, were introduced into a steel angle structure (SAS) which is half of the WTSS and a steel plate respectively for fatigue crack identification and monitoring. Similar approach was used for identifying the fatigue crack. Results show that fatigue cracks can reflect guided waves by reason of discontinuous contact of crack surfaces, and demonstrate the feasibility and effectiveness of the proposed method for real-time monitoring of fatigue cracks in bogie frames of the train.

M. Y. Lu, X. Lu, L. M. Zhou, F. C. Li

The Concept of Operations Assurance and Its Application in Metro Railway

MTR Corporation has established through extensive experience in railway operation an Operations Assurance process to assure the operational safety and service performance of railway network in Hong Kong and for new lines operation outside Hong Kong. This paper provides an overview on the Operation Assurance System which focus on safety assurance of the railway operation, safety critical system software assurance, system reliability, system assurance and new business safety assurance. The Operations Assurance process, which aligns with a risk based Asset Management System of the Corporation, requires appropriate assurance activities to be conducted at different stages of asset life cycle with foci putting on 1) management of changes arising from asset introduction / modification, asset life assurance and their associated operational interfaces, 2) monitoring of asset condition and performance in the whole life cycle, and 3) mitigate the potential hazards due to aging and compatibility of the assets. With the solid platform of the Operations Assurance process and spirit of continuous improvement, MTR Corporation has been achieving a high level of standard in operational safety and service performance that is recognised as world class.

Ronald K. W. Cheng, Ryan C. M. Lam

Risk-Based Railway Systems Design Adopted for the XRL

The paper introduces the risk-based railway systems design approach adopted by the MTR Corporation for its railway projects and the Express Rail Link (XRL) Project, as part of the extension to the Mainland High-speed Rail Network. The risk-based railway systems design is a top-down approach with a clear definition of project objectives, user requirements, functional requirements which serve as a means for mutual agreement amongst stakeholders as well as for calculation and management of risk started in the early stage of the project lifecycle. This approach identifies overall quantifiable performance targets for the railway projects and assigns the relevant targets to responsible systems so as to ensure the final railway project meeting its operation and maintenance needs upon delivery.

This risk-based systems design approach also helps to identify and prepare necessary Operation & Maintenance provisions and procedures during project stage to ensure a safe and up-to-standard service upon opening of the railway. To conclude, the paper talks about how this approach is being adopted for the implementation of the XRL.

C. L. Leung, S. Wong

Study on Reliability of Key Components of Freight Cars Running at High Density

The Da-Qin railway line in China runs 653 kilometers where the heavy haul train of 10,000 and 20,000 gross tons are operated at average interval of 14 minutes continuously without stop for maintenance. The essay focuses on how to improve the reliability of key components of running gear, coupler and draft gear and carbody to ensure safe operation of heavy haul train in high density and running mileage.

Y. B. Yu, H. L. Wei, H. Li, W. Yan, L. D. Li

A Feasibility Study on the Use of Simple Vibration Test in the Detection of Railway Ballast Damage

This paper reports a feasibility study in the use of measured modal parameters of in-situ concrete sleepers to detect possible damage of the underlying railway ballast. There are many methods developed for monitoring and damage detection of the rail track. However, the detection of ballast damage still heavily relies on visual inspection and destructive core test. In this feasibility study, a typical plain ballasted track with concrete sleeper is considered. In the proposed method, ballast under sleeper is modelled as an elastic foundation. Ballast damage is defined as ballast degradation and ballast cementation with the accumulation of fines. When the ballast is damaged, the stiffness provided in supporting the sleeper will reduce, and the vibration characteristic of the in-situ sleeper will be altered. This paper studies the possibility to detect the damage status of ballast under a sleeper by monitoring the vibration of the corresponding sleeper through simple impact hammer test. This paper not only presented the theoretical development but also the numerical verifications.

H. F. Lam, M. T. Wong

The Evolution and Outlook of Core Technologies for High-Speed Railway in China

This paper examines the evolution of the core technologies of Chinese high-speed railway in the context of the three major players worldwide: Japan, France and Germany. Four stages of evolution have been identified: exploration of available technologies, transfer of the best technologies, and assimilation of the acquired technologies and creation of optimum technologies for China’s high-speed railway. The paper focuses and reports on the latest development trends on traction drive and its control, traction power supply and overhead traction current collection systems, mobile communication system and signalling system.

K. K. Lee

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