Optimal profile design for rail grinding based on wheel–rail contact, stability, and wear development in high-speed electric multiple units

2019 ◽  
Vol 234 (6) ◽  
pp. 666-677
Author(s):  
Kai Xu ◽  
Zheng Feng ◽  
Hao Wu ◽  
Dongri Xu ◽  
Fu Li ◽  
...  
Keyword(s):  
High Speed ◽  
Simulation Software ◽  
Single Type ◽  
Large Radius ◽  
Wheel Wear ◽  
Railway Line ◽  
Rail Grinding ◽  
Wheel Profile ◽  
Profile Design ◽  
Multiple Units

High-speed electric multiple units have numerous advantages. However, a number of critical maintenance issues arise in the operation of high-speed electric multiple units. The previous researches about rail profile design usually take only a single type of wheel profile into account, which would cause some other problems such as severe increase of hollow wear on the wheels. This study systematically investigates the influence of rail grinding on running stability and wear development in high-speed electric multiple units and designs a new rail profile as reference for grinding that takes all types of vehicle wheels running on a specific line into account, in order to design a ground rail which could match the wheel profile and thus improve the running stability of electric multiple units. All types of wheel profiles used on the Wuhan–Guangzhou railway line are taken as the design reference. A wheel–rail wear simulation program is constructed based on CONTACT numerical simulation software and SIMPACK vehicle system dynamics software. The simulation results show that both the wheel–rail contact relationship and the running stability of high-speed electric multiple units improved after rail grinding. The results of the wheel wear analysis show that when the rail is ground to the target profile, after a running mileage of 200,000 km, the wear area of the new wheel profile LMA and the greatest hollow wear wheel profile LMA-25 decreases by 1.13 mm2 and 9.86 mm2, respectively. In addition, this method can prolong the wheel reprofiling interval. For the Wuhan–Guangzhou railway line, normally the grinding interval for the tangent track and large-radius curve is 2–3 years, and for the entering and exiting tunnel sections, the grinding interval should be set for 1–2 years, which could remove the damaged layer of the rail surface and could restore the designed profile of the rail and prolong the rail service life.

Improving Punctuality of Train Traffic on Western Main Line of Swedish Railway Network: Simulation Approach

2009 ◽  
Author(s):  
Nilesh Anand ◽  
Michel Anayi
Keyword(s):  
High Speed ◽  
Robustness Analysis ◽  
Simulation Software ◽  
Main Line ◽  
Railway Network ◽  
Factors Affecting ◽  
Capacity Enhancement ◽  
Railway Line ◽  
Rail Network ◽  
Line Section

Western main line is one of the most important railway lines in Sweden. The line section from Stockholm to Katrineholm, which connects the largest cities of the Sweden i.e. Stockholm, Gothenburg and Malmo¨, is studied. This line has heterogeneous train traffic consisting high-speed, regional, freight and commuter trains. This paper attempts to study different factors affecting punctuality on this railway line concentrating on traffic problem around Gnesta station and commuter train turn-back scenario — a bottleneck — at the same station. Simulation of existing and modified timetable is done using train traffic simulation software “Railsys”. Experiments including examining effect of rescheduling train timings, capacity enhancement and infrastructure changes in rail network are conducted and investigated. Robustness analysis is performed from the results of simulation and investigation of the consequences of delays and comparison of how different features in the timetables affect the robustness is done.

scholarly journals HIGH SPEED RAILWAY LINES – FUTURE PART OF CZECH RAILWAY NETWORK?

2017 ◽  
Vol 11 ◽  
pp. 74
Author(s):  
Lukáš Týfa ◽  
David Vodák
Keyword(s):  
High Speed ◽  
Railway Network ◽  
High Speed Rail ◽  
High Speed Railway ◽  
Railway Line ◽  
High Speed Trains ◽  
The One ◽  
Infrastructure Maintenance ◽  
The Relationship ◽  
Multiple Units

The paper first describes high speed rail generally and explains the relationship between high speed and conventional railway networks (according to the vehicle types in operation on the network). The core of the paper is comprised of the methodology for choosing the best route for a railway line and its application to the high speed railway connection Praha – Brno. The Algorithm used assumes the existence of more route proposals, which could be different in terms of the operational conception, line routing or types of vehicles used. The optimal variant is the one with the lowest daily cost, which includes infrastructure and vehicle costs; investment and operational costs. The results from applying this model confirmed the assumption, that a dedicated high speed railway line, only for high speed trains, has the same or lower investment costs than a line for both high speed and conventional trains. Furthermore, a dedicated high line also has a lower cost for infrastructure maintenance but a higher cost for buying high speed multiple units.

Parameter Studies for Wheel Wear Using a Flexible Wheelset

2013 ◽  
Vol 712-715 ◽  
pp. 1230-1234
Author(s):  
Na Wu ◽  
Jing Zeng
Keyword(s):  
High Speed ◽  
Wear Depth ◽  
Wheel Wear ◽  
Wear Model ◽  
Wear Performance ◽  
Flexible Wheelset ◽  
Wheel Profile ◽  
Wheel Profile Wear ◽  
Multi Body ◽  
Equivalent Conicity

In order to reduce wheel profile wear of high-speed train and extend the service life of wheels, a high-speed vehicle multi-body dynamic model and wheel profile wear model are established, in which the wheelset is considered as flexible. The influence of wheel profile, track gauge, and rail cant is extensively studied. The simulation results show that the type XP55 wheel has smallest cumulative wear depth, and type LM wheel has largest wear depth. It is known that the equivalent conicity of the wheel should not be too large or too small. The track gauge with 1435-1438mm and rail cant with 1:35-1:40 can have better wheel wear performance.

scholarly journals Multiview deep learning based on tensor decomposition and its application in fault detection of overhead contact systems

2021 ◽  
Author(s):  
Xuewu Zhang ◽  
Yansheng Gong ◽  
Chen Qiao ◽  
Wenfeng Jing
Keyword(s):  
High Speed ◽  
Tensor Decomposition ◽  
Detection Methods ◽  
Detection Accuracy ◽  
Feature Maps ◽  
Training Time ◽  
Detection Model ◽  
Railway Line ◽  
Result Show ◽  
Deep Layers

AbstractThis article mainly focuses on the most common types of high-speed railways malfunctions in overhead contact systems, namely, unstressed droppers, foreign-body invasions, and pole number-plate malfunctions, to establish a deep-network detection model. By fusing the feature maps of the shallow and deep layers in the pretraining network, global and local features of the malfunction area are combined to enhance the network's ability of identifying small objects. Further, in order to share the fully connected layers of the pretraining network and reduce the complexity of the model, Tucker tensor decomposition is used to extract features from the fused-feature map. The operation greatly reduces training time. Through the detection of images collected on the Lanxin railway line, experiments result show that the proposed multiview Faster R-CNN based on tensor decomposition had lower miss probability and higher detection accuracy for the three types faults. Compared with object-detection methods YOLOv3, SSD, and the original Faster R-CNN, the average miss probability of the improved Faster R-CNN model in this paper is decreased by 37.83%, 51.27%, and 43.79%, respectively, and average detection accuracy is increased by 3.6%, 9.75%, and 5.9%, respectively.

scholarly journals Fully Automated Cultivation of Adipose-Derived Stem Cells in the StemCellDiscovery—A Robotic Laboratory for Small-Scale, High-Throughput Cell Production Including Deep Learning-Based Confluence Estimation

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 575
Author(s):  
Jelena Ochs ◽  
Ferdinand Biermann ◽  
Tobias Piotrowski ◽  
Frederik Erkens ◽  
Bastian Nießing ◽  
...  
Keyword(s):  
Stem Cells ◽  
Deep Learning ◽  
High Throughput ◽  
High Speed ◽  
New Technologies ◽  
Human Mesenchymal Stem Cells ◽  
Simulation Software ◽  
System Capacity ◽  
Small Scale ◽  
Production Environment

Laboratory automation is a key driver in biotechnology and an enabler for powerful new technologies and applications. In particular, in the field of personalized therapies, automation in research and production is a prerequisite for achieving cost efficiency and broad availability of tailored treatments. For this reason, we present the StemCellDiscovery, a fully automated robotic laboratory for the cultivation of human mesenchymal stem cells (hMSCs) in small scale and in parallel. While the system can handle different kinds of adherent cells, here, we focus on the cultivation of adipose-derived hMSCs. The StemCellDiscovery provides an in-line visual quality control for automated confluence estimation, which is realized by combining high-speed microscopy with deep learning-based image processing. We demonstrate the feasibility of the algorithm to detect hMSCs in culture at different densities and calculate confluences based on the resulting image. Furthermore, we show that the StemCellDiscovery is capable of expanding adipose-derived hMSCs in a fully automated manner using the confluence estimation algorithm. In order to estimate the system capacity under high-throughput conditions, we modeled the production environment in a simulation software. The simulations of the production process indicate that the robotic laboratory is capable of handling more than 95 cell culture plates per day.

scholarly journals The use of simulation modelling for determining the capacity of railway lines in the Czech conditions

2020 ◽  
Vol 10 (1) ◽  
pp. 224-231
Author(s):  
Erik Tischer ◽  
Petr Nachtigall ◽  
Jaromír Široký
Keyword(s):  
Czech Republic ◽  
Traffic Flow ◽  
Software Tool ◽  
Simulation Modelling ◽  
Energy Performance ◽  
Simulation Software ◽  
The Czech Republic ◽  
Railway Line ◽  
Specialized Software ◽  
Railway Infrastructure

AbstractSimulation modelling is one way to determine the capacity of railway lines. The specialized software tool OpenTrack was used for simulation. The aim of this paper was to find out whether the OpenTrack simulation software can be used for the calculation of headway, and to compare the results with the methodology of the Railway Infrastructure Administration (SŽDC). Using the software tool, a detailed transport network model can be created including all its important characteristics. The simulation follows the movements and behaviour of trains with predefined parameters on the modelled railway line. OpenTrack allows for monitoring a range of parameters including not only train delays, train conflicts and train traffic flow, but also for instance train energy performance and headways. During the first stage of work with OpenTrack, a simulation model was created, not reflecting any existing infrastructure but including parameters typical of railway lines in the Czech Republic, such as the configuration of gridirons, length of station tracks, size of block sections, etc. This model was subsequently used for the simulation of type train set journeys, and a headway calculator was used for the calculation of headway values. These values were compared with the methodology used by the Railway Infrastructure Administration. The paper is concluded by the comparison of the above mentioned approaches.

Simulation and measurement study of metro wheel wear based on the Archard model

2019 ◽  
Vol 71 (2) ◽  
pp. 284-294 ◽  
Author(s):  
AiHua Zhu ◽  
Si Yang ◽  
Qiang Li ◽  
JianWei Yang ◽  
Xi Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Measured Data ◽  
Sequence Type ◽  
Dynamics Model ◽  
Wheel Wear ◽  
Matlab Software ◽  
Hertz Theory ◽  
Content Type ◽  
Vehicle Load ◽  
Wheel Profile

PurposeThe purpose of this paper is to study the wear evolution of metro wheels under the conditions of different track sequences, track composition and vehicle load and then to predict wheel wear and to guide its maintenance.MethodologyBy using the SIMPACK and MATLAB software, numerical simulation analysis of metro wheel wear is carried out based on Hertz theory, the FASTSIM algorithm and the Archard model. First of all, the vehicle dynamics model is established to calculate the motion relationship and external forces of wheel-rail in the SIMPACK software. Then, the normal force of wheel-rail is solved based on Hertz theory, and the tangential force of wheel-rail is calculated based on the FASTSIM algorithm through the MATLAB software. Next, in the MATLAB software, the wheel wear is calculated based on the Archard model, and a new wheel profile is obtained. Finally, the new wheel profile is re-input into the vehicle system dynamics model in the SIMPACK software to carry out cyclic calculation of wear.FindingsThe results show that the setting order of different curves has an obvious influence on wear when the proportion of the straight track and the curve is fixed. With the increase in running mileage, the severe wear zone is shifted from tread to flange root under the condition of the sequence-type track, but the wheel wear distribution is basically stable for the unit-type track, and their wear growth rates become closer. In the tracks with different straight-curved ratio, the more proportion the curved tracks occupy, the closer the severe wear zone is shifted to flange root. At the same time, an increase in weight of the vehicle load will aggravate the wheel wear, but it will not change the distribution of wheel wear. Compared with the measured data of one city B type metro in China, the numerical simulation results of wheel wear are nearly the same with the measured data.Practical implicationsThese results will be helpful for metro tracks planning and can predict the trend of wheel wear, which has significant importance for the vehicle to do the repair operation. At the same time, the security risks of the vehicle are decreased economically and effectively.Originality/valueAt present, many scholars have studied the influence of metro tracks on wheel wear, but mainly focused on a straight line or a certain radius curve and neglected the influence of track sequence and track composition. This study is the first to examine the influence of track sequence on metro wheel wear by comparing the sequence-type track and unit-type track. The results show that the track sequence has a great influence on the wear distribution. At the same time, the influence of track composition on wheel wear is studied by comparing different straight-curve ratio tracks; therefore, wheel wear can be predicted integrally under different track conditions.

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