scholarly journals Running safety of high-speed train on rigid frame bridge subjected to earthquakes

2018 ◽  
Vol 153 ◽  
pp. 052020
Author(s):  
H J Lei ◽  
J Z Huang
Keyword(s):  
High Speed ◽  
High Speed Train ◽  
Running Safety ◽  
Rigid Frame ◽  
Rigid Frame Bridge

The Vehicle Dynamical Analysis of a High-Speed Train Passing through a Tunnel

2010 ◽  
Vol 29-32 ◽  
pp. 835-840 ◽  
Author(s):  
Zhi Peng Feng ◽  
Ji Ye Zhang ◽  
Wei Hua Zhang
Keyword(s):  
High Speed ◽  
Stokes Equations ◽  
Geometric Model ◽  
Three Dimensional ◽  
Grid Method ◽  
Dynamical Analysis ◽  
High Speed Train ◽  
Flow Induced Vibration ◽  
Running Safety ◽  
Dynamics Calculation

As the speed of train increases, flow-induced vibration of trains passing through tunnels has become a subject of discussion, to investigate this phenomenon, a simplified geometric model and a vehicle dynamics model of a high-speed train traveling through a tunnel were built. To analyze the unsteady three-dimensional flow around the train, the 3-D, transient, viscous, compressible Reynolds-averaged Navier-Stokes equations combined with the k- two-equation turbulence model were solved with the finite volume method. The motion of the train was carried out using the technique of sliding grid method. The dynamics response of the train was obtained by means of the computational multi-body dynamics calculation. Meanwhile the running safety and riding comfort of the train were analyzed. With the numerical simulation, the variation of aerodynamic forces was obtained. The research founds that, vibration of the train increases drastically during it passing through a tunnel. The running safety and riding quality of the train are reduced greatly but they are in the safe range.

Random Analysis of the Safety of a High-Speed Train through a Bridge under Earthquake

2019 ◽  
Author(s):  
Dong-Ho Choi ◽  
Di Mu ◽  
Chunyan Ma ◽  
Min-Wo Park ◽  
Ji-Hoon Lim
Keyword(s):  
High Speed ◽  
Damping Ratio ◽  
Time Lag ◽  
Dynamic Responses ◽  
Cost Calculation ◽  
Load Factor ◽  
High Speed Train ◽  
Three Dimensional Model ◽  
Research Attention ◽  
Running Safety

<p>The widely use of bridge structures in modern high-speed railway makes the possibility that a train face to an earthquake when it’s running on a bridge increased. The running safety of the train requires more research attention to be paid. This study investigated the effect of bridge properties on the running safety of a high- speed train under earthquakes using a fast calculation approach. The train-track-bridge (TTB) system is simplified as a three-dimensional model for the dynamic analysis. The rigid contact between rails and wheels is considered, while the direct coupling iteration approach is adopted to solve the dynamic responses of the TTB system. The track irregularities, wheel hunting motion, and multi-support earthquake, which considers the time lag between the seismic waves at different supports, are considered as the excitations to the TTB system. The randomness of the excitations is considered by the pseudo-excitation method (PEM) and the statistical results of the TTB system random responses are obtained. The derailment factor and the off-load factor are used to evaluate the running safety of the train. In the case study, the damping ratio, pier height, and track eccentricity are considered as the various parameters of the bridge properties. Through the PEM analysis, the mean value and standard deviation of the running safety factors were obtained used to evaluate the running safety of the train under an earthquake condition. The evaluation approach for the running safety used in this study can help the engineers to simply check the designs of the railway bridges without performing large time cost calculation work.</p>

scholarly journals Numerical Study on Track–Bridge Interaction of Integral Railway Rigid-Frame Bridge

2021 ◽  
Vol 11 (3) ◽  
pp. 922
Author(s):  
Wenshuo Liu ◽  
Hao Lai ◽  
Gonglian Dai ◽  
Shiwei Rao ◽  
Dezhi Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Numerical Study ◽  
Threshold Value ◽  
Design Parameters ◽  
Bridge Structure ◽  
Analysis Model ◽  
High Speed Railway ◽  
Rigid Frame ◽  
Track Bridge ◽  
Rigid Frame Bridge

Track–bridge interaction (TBI) is an increasingly essential consideration for the design and operation of railway bridges, especially for the innovative bridge structure systems that constantly spring up over the years. This paper focuses on the characteristics of additional forces in continuous welded rails (CWRs) on the 3 × 70 m integral rigid-frame bridge of the Fuzhou–Xiamen High-Speed Railway, which is a novel high-speed railway (HSR) bridge structure system in China. The differential equations of rail stress and displacement are first investigated and an integrative analysis model comprising of rail, track, bridge and piers is then established. Secondly, the characteristics of representative additional forces are illustrated and the influences of different design parameters are discussed in detail. Furthermore, suitable rail fasteners, optimal layout schemes of adjacent bridges and reasonable stiffness of piers are also studied. The results indicate that the additional expansion force accounts for the largest proportion of additional forces in integral rigid-frame bridges and that resistance reduction obviously weakens the various additional forces caused by the TBI effect, while the broken gap of the rail increases greatly. Small resistance fasteners are recommended to be applied onto this new type of HSR line as these provide reductions in additional stresses of CWRs compared to WJ-8 fasteners. The additional rail stresses after adopting an adjacent span scheme of 4 × 32 m simply supported beams are less than the corresponding stresses in other schemes. The results also show that there is a strong correlation between the minimum threshold value of the pier stiffness and the longitudinal resistance of HSR lines for the integral rigid-frame bridge. This work could serve as a valuable reference for detailed design and safety evaluation of integral rigid-frame bridges.

Running safety evaluation of high-speed train subject to the impact of floating ice collision on bridge piers

2021 ◽  
pp. 095440972110100
Author(s):  
Penghao Li ◽  
Zhonglong Li ◽  
Zhaoling Han ◽  
Shengyang Zhu ◽  
Wanming Zhai ◽  
...  
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
Dynamic Responses ◽  
Impact Loads ◽  
High Speed Train ◽  
Train Track ◽  
Railway Bridges ◽  
Running Safety ◽  
Track Bridge ◽  
The Impact

In Northeast China and the areas along Sichuan-Tibet railway, collision between floating ice and piers of railway bridges seriously threatens the train operation safety. The safety of high-speed train running on the bridge subject to the impact of floating ice collision is rarely assessed considering the spatial interaction of the train-track-bridge-ice system. To evaluate the running safety and ride comfort of trains and the structural stability of railway bridges under the collision between floating ices and piers, a train-track-bridge (TTB) dynamic interaction model considering the impact of floating ice is established. Using the refined finite element model, the collision process of floating ice on bridge pier is simulated, and the impact loads are employed as the excitation input of the TTB dynamics model. Taking a 5 × 32 m simply-supported bridges as a case study, the influence of bridge structural parameters on the floating ice collision system is investigated, and then the dynamic responses of the TTB system induced by the floating ice impact loads are analyzed in detail. Finally, the effect of the ice impact loads on the running safety of the high-speed train is revealed. Results show that under the floating ice impact loads, the angle of the pier sharp-nose (APSN) and lateral stiffness of foundations are the key parameters that influence the dynamic responses of the bridge, and an improperly small lateral stiffness of foundation would lead to an instability of bridge structure. The influence of ice impact loads on the dynamic responses of the train is remarkable. The lateral vibration acceleration, derailment factor and lateral wheel rail force caused by the ice impact loads are all greater than those caused by the track irregularity, while the wheel unloading rate is slightly smaller. In addition, the running speed of train is also closely related to the running safety and ride comfort when the collision occurs. When the train speed exceeds 400 km/h, the train passing through the bridge would have the possibility of derailment.

Two-dimensional analysis of the influence of windbreaks on airflow over a high-speed train under crosswind using lattice Boltzmann method

2017 ◽  
Vol 232 (3) ◽  
pp. 863-872 ◽  
Author(s):  
Masoud Mohebbi ◽  
Mohammad A Rezvani
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
High Speed ◽  
Two Dimensional ◽  
High Speed Train ◽  
Running Safety ◽  
Dimensional Modeling ◽  
High Speed Trains ◽  
The One ◽  
Boltzmann Method

This research is concerned with identifying the effects of windbreak geometry on attenuating aerodynamic loads that can be strong enough to disturb the running safety of high-speed trains. The idea is to suggest the proper geometry for the windbreaks that can make them more efficient and increase their overall performance. Generally speaking, the desired windbreak is the one that can minimize the aerodynamic forces on the surface of trains. In order to reach such an aim, the flow of air around an Intercity-Express 3 high-speed train has been estimated through a two-dimensional modeling by using the lattice Boltzmann method. The flow of crosswind that hits the train is considered as turbulent. The geometry of the windbreaks including the height, the slot, and the edge angles has been investigated. It has been concluded that the windbreak performance, among other parameters, is highly dependent on its height and edge angle. This research expedites the trail for finding suitable choices of windbreak geometries that can in turn provide a reliable degree of running safety of the railway fleet.

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