Dynamic Response of a New Railway Emergency Steel Truss Girder under the Moving Train Loads

2010 ◽  
Vol 139-141 ◽  
pp. 2405-2408
Author(s):  
Yao Hui Zhang ◽  
Hai Long Wang
Keyword(s):  
Traffic Safety ◽  
Dynamic Responses ◽  
Coupling Vibration ◽  
Railway Bridges ◽  
Technical Requirements ◽  
Structural Details ◽  
Steel Truss ◽  
Object Of Study ◽  
Steel Truss Girder ◽  
New Situation

In China, a new railway middle-span emergency steel truss girder, which can adapt to the technical requirements about quickly repairing the damaged railway bridges, is developed under the new situation. The old emergency steel truss girder for the railway bridges can not adapt to the current technical requirements. So, the new railway middle-span emergency steel truss girder (hereinafter referred to as the new girder) is developed after hard work. The great changes on the structure, the connections, the structural details and the multi-purpose have taken place on it compared to the existing old similar girder. In this paper, the structure and technical characteristics of the new girder are introduced. In order to improve the new girder’s design, the dynamic responses of the new girder are calculated using the train-bridge coupling vibration theory. In the paper, the 32m-span girder are the main object of study. The vibration-related laws are revealed versus the different train speeds, and the proposals about the largest traffic safety speed are given.

Dynamic Analysis of 64-Type Rush-Repair Steel Girder under the Moving Train Loads

2011 ◽  
Vol 199-200 ◽  
pp. 87-91
Author(s):  
Yao Hui Zhang ◽  
Hai Long Wang
Keyword(s):  
Traffic Safety ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Dynamic Responses ◽  
Transportation Engineering ◽  
Steel Girder ◽  
Coupling Vibration ◽  
Engineering Construction ◽  
Technical Requirements ◽  
Highway Transportation

In China, the 64-type rush-repair steel girder developed in 1964 has played a huge role in the railway and highway transportation engineering construction. When it is used as a temporary railway bridge, the original biggest design traffic speed only is 30 km/h. With the rapid development of domestic railway, the dynamic performance of the 64-type rush-repair steel girder must be studied in detail in order to make clear what it can adapt the current technical requirements. In the paper, the structure and technical characteristics of the 64-type rush-repair steel girder are introduced and the dynamic responses of the 64-type rush-repair steel girder are calculated using the train-bridge coupling vibration theory. The main objects of study in paper are the 24m-span and 32m-span girders. The vibration-related laws of the 64-type rush-repair steel girder versus the different train speeds are revealed, and the proposals about the largest reasonable traffic safety speed are given.

A model for the vibrator–ground coupling vibration and the dynamic responses under excitation of sweep signal

2019 ◽  
Vol 22 (8) ◽  
pp. 1855-1866 ◽  
Author(s):  
Gang Li ◽  
Zhi-Qiang Huang ◽  
Zhang-Hua Lian ◽  
Lei Hao
Keyword(s):  
Dynamic Stiffness ◽  
Low Frequency ◽  
Dynamic Responses ◽  
Coupling Vibration ◽  
Lower Velocity ◽  
Dynamic Damping ◽  
Velocity Response ◽  
Cell Test ◽  
Three Stages ◽  
Good Agreement

To analyze the behavior of the vibrator–ground coupling vibration, a model containing equivalent dynamic stiffness and equivalent dynamic damping to describe the interaction between the vibrator and the ground is established based on half-space theory. According to load cell test, this model shows a good agreement with the experimental data. Dynamic responses of the structure are analyzed on displacement, velocity, acceleration, and ground force. Results show that the stroke and pump displacement are main constraints that limit the bandwidth of vibrator toward low frequency, and the stroke of conventional vibrator is not long enough to achieve lower frequency. Analysis of velocity response indicates that with the increase of frequency, a larger mass results in a lower velocity under external force. The influence of the ground acting on the baseplate is limited, and the acceleration of the baseplate is determined by its own mass beyond 80 Hz. Analysis of ground force shows that the response of the structure can be divided into three stages. The reaction mass, the baseplate, and the ground play different roles in dominating the ground force at different frequency bands.

An Efficient Non-Iterative Hybrid Method for Analyzing Train–Rail–Bridge Interaction Problems

2020 ◽  
pp. 2150029
Author(s):  
Kang Shi ◽  
Xuhui He ◽  
Yunfeng Zou ◽  
Zhi Zheng
Keyword(s):  
Hybrid Method ◽  
Computational Efficiency ◽  
High Speed ◽  
Low Frequency ◽  
Coupled Analysis ◽  
Time Step ◽  
Coupling Vibration ◽  
Current Time ◽  
Railway Bridges ◽  
Frequency Coupling

The dynamic interaction problem for the train–rail–bridge (TRB) systems presents a computational challenge, especially for the analysis of large-size TRB coupling systems. To address this issue, an efficient non-iterative hybrid method (NHM) is proposed. With this method, the integrated TRB system is divided into three subsystems, i.e. the train subsystem, the rail subsystem, and the bridge subsystem. Based on the individual subsystems, a multi-step[Formula: see text] technique is adopted in which a fine time step is used to analyze the high-frequency coupling vibration for the train and rail subsystems, and a coarse time step is adopted to calculate the low-frequency coupling vibration for the rail and bridge subsystem. Additionally, Zhais explicit integral method is used to predict the displacement of the wheelsets and the rail at the current time step before using the Newmark method. The proposed method incorporates the advantages of Zhai’s explicit method and the MS technique to avoid the iteration that may be required for the train–rail coupled analysis. The simulation fidelity and computational efficiency of the proposed method are demonstrated in the analysis of two examples of typical high-speed railway bridges. It was demonstrated that the proposed method can significantly enhance the computational efficiency, while maintaining a higher precision with a larger time step in comparison with other existing methods.

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

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.

Study on Vehicle-Bridge Coupling Vibration of Equal Span Girder Bridge of Different Span Number

2013 ◽  
Vol 540 ◽  
pp. 63-68
Author(s):  
Wei Zhao Li ◽  
Zong Lin Wang ◽  
Hang Sun ◽  
Yan Li
Keyword(s):  
Surface Roughness ◽  
Influencing Factor ◽  
Dynamic Responses ◽  
Box Girder Bridges ◽  
Coupling Vibration ◽  
Average Value ◽  
Girder Bridges ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Traveling Speed

The vehicle-bridge coupling vibration of girder bridge has been widely investigated. But most of previous work focused on the influencing factor of the vibration, such as traveling speed of vehicle, deck surface roughness and vehicle-bridge frequency ratio etc. Taking the box girder bridges of different span number with 20m single span length for example, applying the separated iterative method to multi-sample analysis the vehicle-bridge coupling vibration. The study considered the influence of the vehicle, traveling speed and the random deck surface roughness and then took the average value of the sample to discuss the influence of the span number on the dynamic responses. Results show that the continuous girder form can effectively decrease the dynamic responses of the equal span girder bridge than the simple-supported form. But the influence of the span number on the responses of equal span continuous girder bridge is not obvious.

Partial Prestressing of Long Span Steel Truss Girder

2013 ◽  
Vol 101 (6) ◽  
pp. 1-4
Author(s):  
Ekasit Limsuwan ◽  
Suchart Chayochaichana ◽  
Uthai Lerksirirat
Keyword(s):  
Long Span ◽  
Steel Truss ◽  
Steel Truss Girder

A Comparative Study on Dynamic Wheel Loads of Multi-Axle Vehicle and Bridge Responses

2001 ◽  
Author(s):  
Chul Woo Kim ◽  
Mitsuo Kawatani
Keyword(s):  
Analytical Procedure ◽  
Three Dimensional ◽  
Highway Bridges ◽  
Dynamic Responses ◽  
Dynamic Factor ◽  
Wheel Load ◽  
Coupling Vibration ◽  
Moving Vehicle ◽  
Speed Parameter ◽  
Bridge Responses

Abstract To investigate relations between dynamic wheel loads of multi-axle vehicles on highway bridges and dynamic responses of bridge due to the vehicular loading, a three-dimensional dynamic analysis is carried out. Simultaneous differential equations for a coupling vibration of bridge and moving vehicle including roadway roughness are derived by means of modal analysis. The analytical wheel loads of vehicle model and responses of bridges are compared with experimental ones, to verify a validity of presented analytical procedure. Parametric investigations show that there exists resemblance between bounce motion of vehicle and bridge response. It can also be seen that the RMS based dynamic factor of dynamic wheel load can give an important information to predict the variation of impact factor of bridge due to speed condition as well as speed parameter.

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