Effects of wind-barrier parameters on dynamic responses of wind-road vehicle–bridge system

2020 ◽  
Vol 206 ◽  
pp. 104367
Author(s):  
Fanrong Xue ◽  
Yan Han ◽  
Yunfeng Zou ◽  
Xuhui He ◽  
Suren Chen
Keyword(s):  
Dynamic Responses ◽  
Road Vehicle ◽  
Wind Barrier ◽  
Bridge System

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

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.

scholarly journals Road Vehicle-Bridge Interaction considering Varied Vehicle Speed Based on Convenient Combination of Simulink and ANSYS

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Helu Yu ◽  
Bin Wang ◽  
Yongle Li ◽  
Yankun Zhang ◽  
Wei Zhang
Keyword(s):  
Reaction Force ◽  
Sudden Change ◽  
Vertical Direction ◽  
Dynamic Responses ◽  
Force Model ◽  
Vertical Acceleration ◽  
Vehicle Speed ◽  
Road Vehicle ◽  
The Road ◽  
Bridge Model

In order to cover the complexity of coding and extend the generality on the road vehicle-bridge iteration, a process to solve vehicle-bridge interaction considering varied vehicle speed based on a convenient combination of Matlab Simulink and ANSYS is presented. In this way, the road vehicle is modeled in state space and the corresponding motion equations are solved using Simulink. The finite element model for the bridge is established and solved using ANSYS. The so-called inter-history iteration method is adopted to realize the interaction between the vehicle model and the bridge model. Different from typical method of road vehicle-bridge interaction in the vertical direction, a detailed longitudinal force model is set up to take into account the effects of varied vehicle speed. In the force model, acceleration and braking of the road vehicle are treated differently according to their mechanical nature. In the case studies based on a simply supported beam, the dynamic performance of the road vehicle and the bridge under varied vehicle speeds is calculated and discussed. The vertical acceleration characteristics of the midpoint of beam under varied vehicle speed can be grouped into two periods. The first one is affected by the load transform between the wheels, and the other one depends on the speed amplitude. Sudden change of the vertical acceleration of the beam and the longitudinal reaction force are observed as the wheels move on or off the bridge, and the bridge performs different dynamic responses during acceleration and braking.

Analysis on Vehicle-Bridge Coupled Vibration of a Rigid-Frame Arch Bridge Based on Measured Road Roughness

2011 ◽  
Vol 255-260 ◽  
pp. 1775-1780
Author(s):  
Wan Shui Han ◽  
Su Jing Yuan ◽  
Bing Wang
Keyword(s):  
High Speed ◽  
Contact Forces ◽  
Dynamic Responses ◽  
Coupled Vibration ◽  
Arch Bridge ◽  
Rigid Frame ◽  
Road Roughness ◽  
Left And Right ◽  
Spectrum Characteristics ◽  
Bridge System

Firstly, synchronous field measurements were carried out for the road roughness of the left and right wheels to obtain the roughness profile using a high speed laser roadway testing vehicle. Secondly, programming idea of multi-girder vehicle-bridge coupled vibration analysis module was presented briefly. Finally, a three-axle heavy truck crossing a rigid-frame arch bridge was taken as an example, detailed comparing and analyzing was carried out for the influence on the dynamic responses and spectrum characteristics of the vehicle-bridge system from three excitation cases which include using measured road roughness corresponding respectively to left and right wheels, using measured road roughness of left wheels and right wheels simultaneously. The analysis shows that when the differences in road roughness between left and right wheels are significant, the responses computed with inconsistent excitation is smaller than that with both of the latter two excitation cases, and there are some differences between the vertical contact forces of wheels and the spectrum characteristics of the vehicle-bridge system.

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

2018 ◽  
Vol 22 (4) ◽  
pp. 919-934 ◽  
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.

scholarly journals Dynamic Responses of a Metro Train-Bridge System under Train-Braking: Field Measurements and Data Analysis

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 735
Author(s):  
Xuhui He ◽  
Kehui Yu ◽  
Chenzhi Cai ◽  
Yunfeng Zou ◽  
Xiaojie Zhu
Keyword(s):  
Field Measurements ◽  
Dynamic Responses ◽  
Wavelet Coherence ◽  
Distribution Method ◽  
Bogie Frame ◽  
Time Frequency ◽  
Rigid Frame ◽  
Rigid Frame Bridge ◽  
Acceleration Signals ◽  
Bridge System

This paper focuses on the dynamic responses of a metro train–bridge system under train-braking. Experiments were performed on the elevated Metro Line 21 of Guangzhou (China). A continuous, three-span, rigid-frame bridge (42 m + 65 m + 42 m) and a standard B-type metro train were selected. The acceleration signals were measured at the center-points of the main span and one side-span, and the acceleration signals of the car body and the bogie frame were measured simultaneously. The train–bridge system’s vibration characteristics and any correlations with time and frequency were investigated. The Choi–Williams distribution method and wavelet coherence were introduced to analyze the obtained acceleration signals of the metro train–bridge system. The results showed that the Choi–Williams distribution provided a more explicit understanding of the time–frequency domain. The correlations between different parts of the bridge and the train–bridge system under braking conditions were revealed. The present study provides a series of measured dynamic responses of the metro train–bridge system under train-braking, which could be used as a reference in further investigations.

scholarly journals Modal and Dynamic Analysis of a Vehicle with Kinetic Dynamic Suspension System

2016 ◽  
Vol 2016 ◽  
pp. 1-18
Author(s):  
Bangji Zhang ◽  
Jie Zhang ◽  
Jinhua Yi ◽  
Nong Zhang ◽  
Qiutan Jin
Keyword(s):  
Dynamic Analysis ◽  
Hydraulic System ◽  
Cooperative Control ◽  
Ride Comfort ◽  
Dynamic Responses ◽  
Analysis Method ◽  
Road Vehicle ◽  
Suspension Systems ◽  
Motion Modes ◽  
Hydraulic Cylinders

A novel kinetic dynamic suspension (KDS) system is presented for the cooperative control of the roll and warp motion modes of off-road vehicles. The proposed KDS system consists of two hydraulic cylinders acting on the antiroll bars. Hence, the antiroll bars are not completely replaced by the hydraulic system, but both systems are installed. In this paper, the vibration analysis in terms of natural frequencies of different motion modes in frequency domain for an off-road vehicle equipped with different configurable suspension systems is studied by using the modal analysis method. The dynamic responses of the vehicle with different configurable suspension systems are investigated under different road excitations and maneuvers. The results of the modal and dynamic analysis prove that the KDS system can reduce the roll and articulation motions of the off-road vehicle without adding extra bounce stiffness and deteriorating the ride comfort. Furthermore, the roll stiffness is increased and the warp stiffness is decreased by the KDS system, which could significantly enhance handing performance and off-road capability.

scholarly journals Running Safety of Trains under Vessel-Bridge Collision

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Yongle Li ◽  
Jiangtao Deng ◽  
Bin Wang ◽  
Chuanjin Yu
Keyword(s):  
Element Model ◽  
Dynamic Responses ◽  
Lateral Acceleration ◽  
Vertical Acceleration ◽  
Running Safety ◽  
Derailment Coefficient ◽  
Parametric Studies ◽  
Train Speed ◽  
Unloading Rate ◽  
Bridge System

To optimize the sensor placement of the health monitoring system, the dynamic behavior of the train-bridge system subjected to vessel-collision should be studied in detail firstly. This study thus focuses on the characteristics of a train-bridge system under vessel-bridge collision. The process of the vessel-bridge collision is simulated numerically with a reliable finite element model (FEM). The dynamic responses of a single car and a train crossing a cable-stayed bridge are calculated. It is shown that the collision causes significant increase of the train’s lateral acceleration, lateral wheelset force, wheel unloading rate, and derailment coefficient. The effect of the collision on the train’s vertical acceleration is much smaller. In addition, parametric studies with various train’s positions, ship tonnage, and train speed are performed. If the train is closer to the vessel-bridge collision position or the ship tonnage is larger, the train will be more dangerous. There is a relatively high probability of running danger at a low speed, resulting from longer stay of the train on the bridge. The train’s position, the ship tonnage, and the train speed must be considered when determining the most adverse conditions for the trains running on bridges under vessel-bridge collision.

Seismic Design Research of Simply Supported Rail-Bridge Based on Running Safety

2014 ◽  
Vol 1065-1069 ◽  
pp. 962-968
Author(s):  
Yan Han ◽  
Xiao Dong Wang
Keyword(s):  
Seismic Design ◽  
Traffic Safety ◽  
Interpolation Method ◽  
Spectral Characteristics ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Analysis Model ◽  
Running Safety ◽  
Simply Supported ◽  
Bridge System

To explore the practical rail-bridge seismic design methods, dynamic response analysis model of the train-rail-bridge system under seismic loads was established, and the widely used simply supported track-bridge in rail transport was taken for the study. By inputting different intensity and frequency artificial seismic waves to the train-rail-bridge system, the whole history of the vehicles running through the bridge is simulated and the dynamic responses of the bridge and the vehicles are calculated. The influence of train type, seismic intensity and spectral characteristics of the earthquake were analyzed. Taking Japanese traffic safety evaluation indexes including derailment coefficient, wheel offload rate and lateral wheel-rail force as evaluation criteria, the allowed lateral bridge displacement limits and acceleration limits that ensuring train running safety under earthquake were obtained, and the bridge vibration limit curve was drawn. Using Lagrange interpolation method, the mathematical expression of the curve was worked out, which can provide a reference to rail-bridge aseismic design.

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