A coupled model for train-track-bridge stochastic analysis with consideration of spatial variation and temporal evolution

In order to study the influence of an integration time step on dynamic calculation of a vehicle-track-bridge under high-speed railway, a vehicle-track-bridge (VTB) coupled model is established. The influence of the integration time step on calculation accuracy and calculation stability under different speeds or different track regularity states is studied. The influence of the track irregularity on the integration time step is further analyzed by using the spectral characteristic of sensitive wavelength. According to the results, the disparity among the effect of the integration time step on the calculation accuracy of the VTB coupled model at different speeds is very small. Higher speed requires a smaller integration time step to keep the calculation results stable. The effect of the integration time step on the calculation stability of the maximum vertical acceleration of each component at different speeds is somewhat different, and the mechanism of the effect of the integration time step on the calculation stability of the vehicle-track-bridge coupled system is that corresponding displacement at the integration time step is different. The calculation deviation of the maximum vertical acceleration of the car body, wheel-sets and bridge under the track short wave irregularity state are greatly increased compared with that without track irregularity. The maximum vertical acceleration of wheel-sets, rails, track slabs and the bridge under the track short wave irregularity state all show a significant declining trend. The larger the vibration frequency is, the smaller the range of integration time step is for dynamic calculation.

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Influences of Wind Barriers on the Train Running Safety on a Highway-Railway One-Story Bridge

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455421400095 ◽

2021 ◽

pp. 2140009

Author(s):

Ye Liu ◽

Yan Han ◽

Peng Hu ◽

C. S. Cai ◽

Xuhui He

Keyword(s):

Dynamic Responses ◽

Response Analysis ◽

Train Track ◽

Wheel Load ◽

Wind Barrier ◽

The Mean ◽

Wind Pressures ◽

Track Bridge ◽

Fluctuating Wind ◽

Bridge System

In this study, the influences of wind barriers on the aerodynamic characteristics of trains (e.g. a CRH2 train) on a highway-railway one-story bridge were investigated by using wind pressure measurement tests, and a reduction factor of overturning moment coefficients was analyzed for trains under wind barriers. Subsequently, based on a joint simulation employing SIMPACK and ANSYS, a wind–train–track–bridge system coupled vibration model was established, and the safety and comfort indexes of trains on the bridge were studied under different wind barrier parameters. The results show that the mean wind pressures and fluctuating wind pressures on the trains’ surface decrease generally if wind barriers are used. As a result, the dynamic responses of the trains also decrease in the whole process of crossing the bridge. Of particular note, the rate of the wheel load reductions and lateral wheel-axle forces can change from unsafe states to relative safe states due to the wind barriers. The influence of the porosity of the wind barriers on the mean wind pressures and fluctuating wind pressures on the windward sides and near the top corner surfaces of the trains are significantly greater than the influence from the height of the wind barriers. Within a certain range, decreasing the wind barrier porosities and increasing the wind barrier heights will significantly reduce the safety and comfort index values of trains on the bridge. It is found that when the porosity of the wind barrier is 40%, the optimal height of the wind barrier is determined as approximately 3.5[Formula: see text]m. At this height, the trains on the bridges are safer and run more smoothly and comfortably. Besides, through the dynamic response analysis of the wind–train–track–bridge system, it is found that the installation of wind barriers in cases with high wind speeds (30[Formula: see text]m/s) may have an adverse effect on the vertical vibration of the train–track–bridge system.

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High-speed train–track–bridge dynamic interactions – Part I: theoretical model and numerical simulation

International Journal of Rail Transportation ◽

10.1080/23248378.2013.791498 ◽

2013 ◽

Vol 1 (1-2) ◽

pp. 3-24 ◽

Cited By ~ 168

Author(s):

Wanming Zhai ◽

He Xia ◽

Chengbiao Cai ◽

Mangmang Gao ◽

Xiaozhen Li ◽

...

Keyword(s):

Numerical Simulation ◽

Theoretical Model ◽

High Speed ◽

High Speed Train ◽

Train Track ◽

Dynamic Interactions ◽

Track Bridge

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Train–track–bridge modelling and review of parameters

Structure and Infrastructure Engineering ◽

10.1080/15732479.2015.1076854 ◽

2015 ◽

Vol 12 (9) ◽

pp. 1051-1064 ◽

Cited By ~ 29

Author(s):

Daniel Cantero ◽

Therese Arvidsson ◽

Eugene OBrien ◽

Raid Karoumi

Keyword(s):

Train Track ◽

Track Bridge

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Vibration Isolation Performance of Floating Slab Track Using a Time Domain Train-Track-Tunnel Coupled Model

ICRT 2017 ◽

10.1061/9780784481257.002 ◽

2018 ◽

Author(s):

Jianjin Yang ◽

Wanming Zhai ◽

Xiaoan Zhang

Keyword(s):

Time Domain ◽

Vibration Isolation ◽

Coupled Model ◽

Train Track ◽

Slab Track ◽

Vibration Isolation Performance ◽

Isolation Performance

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An Alternative Solution of Train-Track Dynamic Interaction

Shock and Vibration ◽

10.1155/2019/1859261 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14

Author(s):

Zhaowei Chen ◽

Hui Fang

Keyword(s):

Calculation Method ◽

Secondary Development ◽

Train Track ◽

Computational Accuracy ◽

Explicit Integration ◽

Application Range ◽

Computing Platform ◽

Development Technology ◽

Railway Engineering ◽

Track Bridge

Train-track interaction (TTI) is a classic research topic in railway engineering, which consists of three main parts, namely, train model, track model, and wheel-rail interaction. To improve the computational accuracy and broaden the application range, an alternative calculation method to investigate TTI based on secondary development technology of the commercial software ANSYS through APDL language is introduced in this article. Primarily, the train-track interaction theory is briefly presented. On this basis, TTI is programmed and implemented on the computing platform of ANSYS by fully taking the nonlinear wheel-rail interaction into consideration. In this calculation method, the train model, which is established based on multibody dynamics theory and solved by an advanced explicit integration method, is programmed into ANSYS through APDL language, while the track part is simulated according to finite element theory. Then, the proposed calculation method is validated with field test results to verify the validity. Finally, a numerical demonstration is conducted employing the present method. Results show that the introduced method is effective and able to investigate TTI. Different complicated track systems can be accurately simulated employing this method. Moreover, this method is also adoptable to explore train-bridge interaction and train-track-bridge interaction.

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Effect of Bridge-Pier Differential Settlement on the Dynamic Response of a High-Speed Railway Train-Track-Bridge System

Mathematical Problems in Engineering ◽

10.1155/2017/8960628 ◽

2017 ◽

Vol 2017 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Xiaohui Zhang ◽

Yao Shan ◽

Xinwen Yang

Keyword(s):

Dynamic Response ◽

High Speed ◽

Tensile Force ◽

Differential Settlement ◽

Bridge Pier ◽

Vertical Acceleration ◽

Train Track ◽

Allowable Limit ◽

High Speed Railway ◽

Track Bridge

A model based on the theory of train-track-bridge coupling dynamics is built in the article to investigate how high-speed railway bridge pier differential settlement can affect various railway performance-related criteria. The performance of the model compares favorably with that of a 3D finite element model and train-track-bridge numerical model. The analysis of the study demonstrates that all the dynamic response for a span of 24 m is slightly larger than that for a span of 32 m. The wheel unloading rate increases with pier differential settlement for all of the calculation conditions considered, and its maximum value of 0.695 is well below the allowable limit. Meanwhile, the vertical acceleration increases with pier differential settlement and train speed, respectively, and the values for a pier differential settlement of 10 mm and speed of 350 km/h exceed the maximum allowable limit stipulated in the Chinese standards. On this basis, a speed limit for the exceeding pier differential settlement is determined for comfort consideration. Fasteners that had an initial tensile force due to pier differential settlement experience both compressive and tensile forces as the train passes through and are likely to have a lower service life than those which solely experience compressive forces.

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Dynamic analysis of coupled train–track–bridge system subjected to debris flow impact

Advances in Structural Engineering ◽

10.1177/1369433218785643 ◽

2018 ◽

Vol 22 (4) ◽

pp. 919-934 ◽

Cited By ~ 1

Author(s):

Xun Zhang ◽

Zhipeng Wen ◽

Wensu Chen ◽

Xiyang Wang ◽

Yan Zhu

Keyword(s):

Debris Flow ◽

Dynamic Analysis ◽

High Speed ◽

Impact Load ◽

Dynamic Responses ◽

Train Track ◽

Running Safety ◽

Track Bridge ◽

Safety Indices ◽

Bridge System

With the increasing popularity of high-speed railway, more and more bridges are being constructed in Western China where debris flows are very common. A debris flow with moderate intensity may endanger a high-speed train traveling on a bridge, since its direct impact leads to adverse dynamic responses of the bridge and the track structure. In order to address this issue, a dynamic analysis model is established for studying vibrations of coupled train–track–bridge system subjected to debris flow impact, in which a model of debris flow impact load in time domain is proposed and applied on bridge piers as external excitation. In addition, a six-span simply supported box girder bridge is considered as a case study. The dynamic responses of the bridge and the running safety indices such as derailment factor, offload factor, and lateral wheel–rail force of the train are investigated. Some influencing factors are then discussed based on parametric studies. The results show that both bridge responses and running safety indices are greatly amplified due to debris flow impact loads as compared with that without debris flow impact. With respect to the debris flow impact load, the boulder collision has a more negative impact on the dynamic responses of the bridge and train than the dynamic slurry pressure. Both the debris flow impact intensity and train speed determine the running safety indices, and the debris flow occurrence time should be also carefully considered to investigate the worst scenario.

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Mapping relationship between dynamic responses of high-speed trains and additional bridge deformations

Journal of Vibration and Control ◽

10.1177/1077546320936899 ◽

2020 ◽

pp. 107754632093689

Author(s):

Hongye Gou ◽

Chang Liu ◽

Hui Hua ◽

Yi Bao ◽

Qianhui Pu

Keyword(s):

High Speed ◽

Coupled Model ◽

Dynamic Responses ◽

High Speed Railway ◽

Railway Bridges ◽

Running Safety ◽

High Speed Trains ◽

Track Bridge ◽

The Relationship ◽

Track Deformation

Deformations of high-speed railways accumulate over time and affect the geometry of the track, thus affecting the running safety of trains. This article proposes a new method to map the relationship between dynamic responses of high-speed trains and additional bridge deformations. A train–track–bridge coupled model is established to determine relationship between the dynamic responses (e.g. accelerations and wheel–rail forces) of the high-speed trains and the track deformations caused by bridge pier settlement, girder end rotation, and girder camber. The dynamic responses are correlated with the track deformation. The mapping relationship between bridge deformations and running safety of trains is determined. To satisfy the requirements of safety and riding comfort, the suggested upper thresholds of pier settlement, girder end rotation, and girder camber are 22.6 mm, 0.92‰ rad, and 17.2 mm, respectively. This study provides a method that is convenient for engineers in evaluation and maintenance of high-speed railway bridges.

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