Study on Critical Speed of Freight Train Derailment on Bridges

2013 ◽  
Vol 639-640 ◽  
pp. 456-459
Author(s):  
Zhi Hui Zhou ◽  
Guo Liu ◽  
Zhi Dong Qian ◽  
Ying Wen ◽  
Qing Yuan Zeng
Keyword(s):  
Critical Speed ◽  
Freight Train ◽  
Train Derailment ◽  
Running Safety ◽  
Vibration Stability ◽  
Track System ◽  
Movement Stability ◽  
Lateral Rigidity ◽  
System Movement ◽  
Energy Increment

The mechanism of train derailment was demonstrated to be the loss of lateral vibration stability of train-bridge (track) system. Based on the theory of energy increment analysis for system movement stability, the energy increment criterion for derailment evaluation and the method of analyzing critical speed of train derailment Vcr were presented. The critical speed of empty freight train on Laoluanhe bridge, Huanghe bridge and Youshui bridge were calculated as 65.2 km/h，64.8 km/h and 66.5 km/h respectively, which were close to actual derailment speed. It is manifested that the method of analyzing critical speed of train derailment is reasonable. According to the calculated results of the critical speed on bridges with different lateral rigidity, it is testified that the critical speed of train derailment rises with the bridge lateral rigidity strengthened. The measure to prevent derailment on bridge is to ensure enough bridge lateral rigidity to meet the running safety of train.

Study on Stability of Lateral Vibration for Train-Bridge (Track) System

2011 ◽  
Vol 255-260 ◽  
pp. 4017-4021
Author(s):  
Zhi Hhui Zhou ◽  
Lu Yang ◽  
Li Ke Lin ◽  
Qing Yuan Zeng
Keyword(s):  
Stability Analysis ◽  
Critical Speed ◽  
Lateral Vibration ◽  
Freight Train ◽  
Train Derailment ◽  
Vibration Stability ◽  
Track System ◽  
Movement Stability ◽  
System Movement ◽  
Energy Increment

The mechanism of train derailment is demonstrated to be the loss of the lateral vibration stability of train-bridge (track) system. Based on the theory of energy increment analysis for system movement stability, the method of stability analysis of lateral vibration for train-bridge (track) system and the energy increment criterion for derailment evaluation are put forward. The method of analyzing critical speed of train derailment is proposed on the basis of the energy increment criterion for derailment evaluation. The critical speed of freight train derailment on Youshui bridge and Laoluanhe bridge are calculated as 66.5 km/h and 65.2 km/h respectively, which are close to actual derailment speed 70 km/h. It is manifested that the method of stability analysis of lateral vibration for train-bridge (track) system is reasonable. The critical speed of train derailment on the Yanconggou bridge of Jingtong line are calculated as 73.0 km/h, and the results has provided important reference for operation department to take appropriate measures.

Running safety evaluation of a 350 km/h high-speed freight train negotiating a curve based on the arbitrary Lagrangian-Eulerian method

2021 ◽  
pp. 095440972098628
Author(s):  
Gongxun Deng ◽  
Yong Peng ◽  
Chunguang Yan ◽  
Boge Wen
Keyword(s):  
High Speed ◽  
Safety Evaluation ◽  
Interaction Model ◽  
Arbitrary Lagrangian Eulerian ◽  
Railway Transportation ◽  
Freight Train ◽  
Fluid Structure ◽  
Running Safety ◽  
Study Results ◽  
Fill Level

To adapt to the rapid growth of the logistics market and further improve the competitiveness of railway transportation, the high-speed freight train with a design speed of 350 km/h is being developed in China. The safety of the train under great axle load of 17 t and dynamic load is unknown. This paper is aimed to study the running safety of the high-speed freight train coupled with various cargo loading conditions negotiating a sharp curve at high velocity. A numerical model integrated a fluid-structure coupled container model and the nonlinear high-speed freight train was set up by the software of LS-DYNA. The fluid-structure interaction model between the container and fluid cargo was established using the Arbitrary Lagrangian-Eulerian (ALE) method. Two influencing parameters, including the cargo state in the container and the fill level, were selected. The study results showed that the wheelset unloading ratio and overturning coefficient could be significantly affected by the liquid sloshing, while the influence of sloshing on the risk of derailment was slight. In general, increasing the cargo filling rate would contribute to vehicle operation safety. In conclusion, this study would provide theoretical help for the running safety of the newly designed high-speed freight train.

scholarly journals An integrated numerical framework to investigate the running safety of overlong freight trains

2020 ◽  
Vol 235 (1) ◽  
pp. 47-60
Author(s):  
Visakh V Krishna ◽  
Daniel Jobstfinke ◽  
Stefano Melzi ◽  
Mats Berg
Keyword(s):  
Compressive Force ◽  
Radio Communication ◽  
Freight Train ◽  
Running Safety ◽  
Loading Patterns ◽  
Train Operation ◽  
Train Dynamics ◽  
Fail Safe ◽  
P Type ◽  
Brake Block

Long freight trains up to 1500 m in length are currently not in regular operation in Europe. One of the important reasons for the same is high inter-wagon forces generated during the operation, especially when pneumatic (P-type) brake systems are used. For long trains with multiple locomotives at different positions along the train, radio communication with necessary fail-safe mechanisms can be used to apply the brakes. Long freight train operation on a given line is subjected to various attributes such as braking/traction scenarios, loading patterns, wagon geometries, brake-block materials, buffer types, track design geometries, etc., which are referred to as heterogeneities. The complex longitudinal train dynamics arising in the train due to various heterogeneities play a major role in determining its running safety. In this context, the maximum in-train force refers to the maximum force developed between any two wagons along the train during operation. The tolerable longitudinal compressive force is the maximum compressive force that can be exerted on a wagon without resulting in its derailment. Here, the authors adopt a bottom-up approach to model pneumatic braking systems and inter-wagon interactions in multibody simulation environments to study the complex longitudinal train dynamics behavior and estimate maximum in-train forces and tolerable longitudinal compressive forces, subjected to various heterogeneities. These two force quantities intend to facilitate a given freight train operation by providing guidelines regarding the critical heterogeneities, that currently limit its safe operation. In doing so, the authors propose the notion to have an operation-based approval for long freight trains using the simulations-based tool.

scholarly journals Dynamic Responses of Vehicle-CRTS III Slab Track System and Vehicle Running Safety Subjected to Uniform Seismic Excitation

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ping Lou ◽  
Kailun Gong ◽  
Chen Zhao ◽  
Qingyuan Xu ◽  
Robert K. Luo
Keyword(s):  
Reduction Rate ◽  
Seismic Intensity ◽  
Dynamic Responses ◽  
Seismic Excitation ◽  
Wheel Load ◽  
Running Speed ◽  
Running Safety ◽  
Slab Track ◽  
Track System ◽  
Highly Sensitive

The dynamic model for the vehicle-CRTS III slab track system is established subjected to uniform seismic excitation, and the calculation program with MATLAB is compiled and verified. The influences of track parameters, seismic intensity, and running speed of the vehicle on the dynamic responses of the system and the vehicle running safety are analyzed. The results show that (1) the track parameters have certain influence on the dynamic responses of the system, and the seismic intensity and the running speed of the vehicle have important influence on the vehicle running safety; (2) the derailment coefficient is highly sensitive to seismic intensity, and the wheel load reduction rate is also highly sensitive to the running speed of the vehicle.

MECHANISM AND ENERGY RANDOM ANALYSIS OF TRAIN DERAILMENT ON RAILWAY BRIDGES

2009 ◽  
Vol 09 (04) ◽  
pp. 585-605 ◽  
Author(s):  
J. XIANG ◽  
Q. Y. ZENG
Keyword(s):  
Transverse Vibration ◽  
Preventive Measure ◽  
Railway Bridges ◽  
Train Derailment ◽  
Whole Process ◽  
Exciting Source ◽  
System 2 ◽  
Energy Increment ◽  
Dynamics Stability ◽  
Stability Concepts

In this paper, the mechanism of train derailment on bridge is developed by applying the system dynamics stability concepts. The theory of energy random analysis for train derailment on bridge is put forward. The contents of the theory are as follows: (1) establishing vibration equation set for the train–bridge system; (2) determining exciting source of transverse vibration of the system; (3) method of energy random analysis of transverse vibration of the system; (4) geometric rules of derailment; (5) calculation of the whole process of train derailment on bridge; (6) criteria of energy increment for judging train derailment on bridge. Finally, three cases concerning train derailment on bridges are treated that coincide with actual conditions. Some main conclusions obtained are: (1) insufficient transversal rigidity of bridge is the reason causing train derailment on bridge and (2) enhancing transversal rigidity of bridge is the main preventive measure against train derailment on bridge.

The effect of train composition on the running safety of low-flatcar wagons in braking and curving manoeuvres

2016 ◽  
Vol 231 (6) ◽  
pp. 666-677 ◽  
Author(s):  
Egidio Di Gialleonardo ◽  
Gabriele Cazzulani ◽  
Stefano Melzi ◽  
Francesco Braghin
Keyword(s):  
Numerical Simulations ◽  
Dynamic Behaviour ◽  
Good Alternative ◽  
Critical Conditions ◽  
Railway Vehicle ◽  
Freight Train ◽  
Running Safety ◽  
Experimental Campaign ◽  
Important Impact ◽  
Truck Transportation

Low-flatcar wagons represent a good alternative to freight truck transportation. In fact, the whole truck can be easily loaded on these wagons. However, due to the railway vehicle gauge, these vehicles present a particular design with an important impact on the dynamics of the trainset and on its derailment risk. The present work aims at analysing the dynamic behaviour of the trainset and the influence of the freight train composition on the derailment risk. Numerical simulations have been performed to identify the most critical conditions. Then, an experimental campaign has been carried out to evaluate the derailment risk associated to these conditions.

scholarly journals Full-Scale Train Derailment Testing and Analysis of Post-Derailment Behavior of Casting Bogie

2019 ◽  
Vol 10 (1) ◽  
pp. 59 ◽  
Author(s):  
Hyun-Ung Bae ◽  
Jiho Moon ◽  
Seung-Jae Lim ◽  
Jong-Chan Park ◽  
Nam-Hyoung Lim
Keyword(s):  
Test Data ◽  
Full Scale ◽  
Lateral Movement ◽  
Freight Train ◽  
Train Derailment

In this study, a full-scale train bogie derailment test was conducted. For this, test methodologies to describe the wheel-climbing derailment of the train bogie and to obtain accurate test data were proposed. The derailment test was performed with the casting bogie for a freight train and a Rheda 2000 concrete track. Two different derailment velocities (28.08 km/h and 55.05 km/h) were considered. From the test, it was found that humps in the concrete track affected the post-derailment behavior of the bogie when the derailment velocity was 28.08 km/h. For a higher derailment velocity (55.05 km/h), significant lateral movement of the derailed bogie was observed. This lateral movement was first controlled by wheel–rail contact, followed by contact with the containment wall. Finally, the train was returned to the track center.

The Hi-Lo Bi-Track System

Joint Rail ◽  
2004 ◽  
Author(s):  
Brian T. Scales
Keyword(s):  
Energy Consumption ◽  
High Speed ◽  
Innovative Technology ◽  
Freight Train ◽  
Speed Reduction ◽  
Low Speed ◽  
Line Speed ◽  
Track System ◽  
Passenger Trains

The Hi-Lo Bi-Track System is an innovative technology that provides appropriate superelevations on curves to suit both high-speed passenger trains and low-speed freight trains. Adoption of the Hi-Lo Bi-Track System would provide the following benefits: • Permit creation of high-speed lines for passenger trains over existing freight train rights-of-way without compromising performance of either train technology. • Provide improvement in typical train trip times due to reduced need for speed reduction at curves. • Provide savings in energy consumption due to less braking for curves and subsequent acceleration back to line speed. • Provide better performance then “tilting trains” in reducing typical train trip times. • Avoid high vertical and lateral track forces resulting from operation of “tilting trains.” • Applicable to high-speed mail and express freight trains in addition to high-speed passenger trains.

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