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.

Running safety evaluation of a train moving over a high-speed railway viaduct under different track conditions

2021 ◽  
Vol 121 ◽  
pp. 105133
Author(s):  
M.A. Peixer ◽  
P.A. Montenegro ◽  
H. Carvalho ◽  
D. Ribeiro ◽  
T.N. Bittencourt ◽  
...  
Keyword(s):  
High Speed ◽  
Safety Evaluation ◽  
High Speed Railway ◽  
Running Safety

Running Safety Assessment of Trains on Bridges under Earthquakes Based on Spectral Intensity Theory

2021 ◽  
Author(s):  
Wei Guo ◽  
Yang Wang ◽  
Hanyun Liu ◽  
Yan Long ◽  
Lizhong Jiang ◽  
...  
Keyword(s):  
High Speed ◽  
Safety Assessment ◽  
Low Frequency ◽  
Interaction Model ◽  
Spectral Intensity ◽  
Dynamic Responses ◽  
Running Safety ◽  
High Speed Trains ◽  
Track Bridge ◽  
Multi Body

The main goal of this paper is to perform the safety assessment of high-speed trains (HSTs) on the simply supported bridges (SSBs) under low-level earthquakes, which are frequently encountered by HSTs, utilizing spectral intensity (SI) index. First, the HST’s limit displacements, which are calculated by using the multi-body train model with detailed wheel–rail relationship, varying with train speed, frequency and amplitude of a sinusoidal base excitation are obtained. Then, based on the obtained HST’s limit displacements, the spectral intensity limits (SIL) graded by the train’s running speed are calculated, and the relationship between the bridge seismic dynamic responses and the train’s running safety was established. Next, the method that utilizes the SI and the SIL indexes to evaluate the HST’s running safety was proposed and verified by comparing with the evaluation result of the train–track–bridge interaction model. Based on the proposed SI index, the HST’s running safety on the SSBs was evaluated under earthquakes, considering different pier heights and site types. The results showed that the low-frequency components of the ground motions are unfavorable to the HST’s running safety, and the height of bridge piers has a significant impact on running safety.

Numerical Approximation of Fluid Structure Interaction (FSI) Problem

2013 ◽  
Author(s):  
Bhuiyan Shameem Mahmood Ebna Hai
Keyword(s):  
High Speed ◽  
Fluid Structure Interaction ◽  
Navier Stokes ◽  
Arbitrary Lagrangian Eulerian ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Reinforced Plastics ◽  
Advanced Composite Materials ◽  
Special Cases ◽  
The Impact

Nowadays, advanced composite materials such as carbon fiber reinforced plastics (CFRP) are being applied to many aircraft structures in order to improve performance and reduce weight. Most composites have strong, stiff fibres in a matrix which is weaker and less stiff. However, aircraft wings can break due to Fluid-Structure Interaction (FSI) oscillations or material fatigue. The airflow around an airplane wing causes the wing to deform, while a wing deformation causes a change in the air pattern around it. Due to thrust force, turbulent flow and high speed, fluid-structure interaction (FSI) is very important and arouses complex mechanical effects. Due to the non-linear properties of fluids and solids as well as the shape of the structures, only numerical approaches can be used to solve such problems. The principal aim of this research is to explore and understand the behaviour of the fluid-structure interaction during the impact of a deformable material (e.g. an aircraft wing) on air. This project focuses on the analysis of Navier-Stokes and elastodynamic equations in the arbitrary Lagrangian-Eulerian (ALE) frameworks in order to numerically simulate the FSI effect on a double wedge airfoil. Since analytical solutions are only available in special cases, the equation needs to be solved by numerical methods. Of all methods, the finite element method was chosen due to its special characteristics and for its implementation, the software package DOpElib.

Simulation of the Interaction Between a Slender Flexible Cylinder and an Axial High-Speed Air Flow

2017 ◽  
Author(s):  
Joris Degroote ◽  
Ine Hertens ◽  
Akil Osman ◽  
Jan Vierendeels
Keyword(s):  
High Speed ◽  
Dynamic Equilibrium ◽  
Air Flow ◽  
Fluid Structure Interaction ◽  
Propagation Speed ◽  
Cylindrical Body ◽  
Arbitrary Lagrangian Eulerian ◽  
Flexible Cylinder ◽  
Fluid Structure ◽  
Structure Interaction

This research analyzes the interaction between fibers and the air jets that are used to accelerate them in fiber processing industries. Typically, supersonic flow is used to achieve sufficiently high thread speeds. However, this flow contains shocks and expansions, resulting in large longitudinal variations in force on the thin and flexible thread. Consequently, a complex fluid-structure interaction (FSI) occurs between the supersonic air flow and the thread. In this research, the fluid-structure interaction between a supersonic air flow and a thread is studied numerically using three-dimensional simulations. The thread is represented by a smooth and flexible cylindrical body. The displacement of the thread is calculated for a given traction on its surface using a finite element structural dynamics code. The compressible flow around the thread is calculated using a finite volume computational fluid dynamics (CFD) code, using the arbitrary Lagrangian-Eulerian (ALE) framework to account for the thread deformation. In these partitioned simulations, the kinematic and dynamic equilibrium conditions on the fluid-structure interface are satisfied using a coupling algorithm. Two coupling algorithms are compared and the influence of numerical parameters is investigated. The fluid-structure interaction simulations reveal transversal running waves in the thread. By comparing the speed of these waves with the propagation speed of the shock waves in the tube, it can be concluded that these phenomena are not related.

scholarly journals Verification of Running Safety Evaluation Method for High-speed Railway

2014 ◽  
Vol 23 (3) ◽  
pp. 310-317 ◽  
Author(s):  
Sang-Hyun Ryu ◽  
Sang-Soo Kim ◽  
Dae-Sik Kim ◽  
Sang-Young Kim ◽  
June-Hee Hong ◽  
...  
Keyword(s):  
High Speed ◽  
Evaluation Method ◽  
Safety Evaluation ◽  
High Speed Railway ◽  
Running Safety

scholarly journals HIGH SPEED FREIGHT TRAIN FOR TRANSPORTATION OF CONTAINERS AT SPEED OF 200 KM/H

2021 ◽  
pp. 70-84
Author(s):  
О.М. Safronov ◽  
◽  
A.O. Sulim ◽  
Yu.Ya. Vodiannikov ◽  
O.G. Маkeieva ◽  
...  
Keyword(s):  
High Speed ◽  
Rolling Stock ◽  
General View ◽  
The European Union ◽  
Railway Transportation ◽  
Freight Train ◽  
Technical Requirements ◽  
Foreign Countries ◽  
Spring Suspension ◽  
Train Speed

The article is devoted to building of freight trains for transportation of containers with railway transport at speed of 200 km/h. The article considers building experience of the high speed freight trains for transportation of containers at speed of 350 km/h. Main technical characteristics of the rolling stock, involved in freight high speed railway transportation in foreign countries are analyzed. The purpose of the article is to discover design features of the rolling stock for freight transportations at speed of 200 km/h and in modeling of the braking processes during electro pneumatic and pneumatic braking of the rolling stock from speed of 200 km/h to 160 km/h. The concept of the rolling stock for high speed freight transportation of containers is proposed. A specialized platform with bogies, disc brake and air-spring suspension Installed on it is used as a rolling stock. A brief description of the brake system is given; its main features are shown. A pneumatic scheme of the container block of the braking equipment and the general view of container block is given. Classified freight train, which consists of 30 platform cars and has two locomotives on each side is proposed for high speed transportation. Brake distance during electro pneumatic and pneumatic braking at freight train speed of 160 km/h is calculated. The results of calculated studies of the trains braking efficiency are given, which showed that at the speed of the freight train of 200 km/h, the brake distances at electro pneumatic and pneumatic braking are represented by 1472 m and 1571 m respectively, which corresponds to the technical requirements of the European Union TSI. Key words: high-speed freight trains, container, speed, brake distance, disc brakes.

Dynamic Characteristics of High Speed Vehicle Passing over Railway Turnout on Bridge

2012 ◽  
Vol 455-456 ◽  
pp. 1438-1443 ◽  
Author(s):  
Rong Chen ◽  
Wang Ping
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Freight Train ◽  
Vertical Stiffness ◽  
Running Safety ◽  
Simply Supported ◽  
Derailment Coefficient ◽  
Load Fluctuation ◽  
Dynamic Simulation Model ◽  
Track Bridge

Based on principle of vehicle-track-bridge dynamic interaction, a dynamic simulation model of a high-speed electric multiple units (EMUs) passing over turnout on bridge was established. The calculation focused on 200km/h No.12 improved ballasted turnout (60kg/m rail) being laid on 3×32.0m simply supported beam, it analyze dynamic characteristics of a freight train with 25t axle load passing at speed of 120km/h and those of CRH1 EMUs passing at speed of 200km/h. Results show that: when the freight train passes the turnout through the main line, the vertical stiffness of the simply supported beams is not sufficient due to the relatively high speed and large axle load; when the EMUs passes the turnout on bridge, the dynamic deflection change rates of girders at the switch and frog are great and the turnout is not appropriately set on the bridge, so the frog crosses over the beam gap, which results in the increasing of track irregularity and finally causes derailment coefficient of vehicle to overrun to reduce the running safety; when a train passes the turnout zone on bridge, interaction between the vehicle and turnout is significant because of load fluctuation of the wheel caused by inevitable structural irregularity at the switch and nose rail, and this requires strengthening measurement and running within speed limit.

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