scholarly journals Dynamic Coupling Analysis of Vehicle-Bridge System for Long-Span Suspension Bridge Based on Backpropagation Neural Network Method

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Zuolong Luo ◽  
Xiaobo Zheng ◽  
Haoyun Yuan ◽  
Xirong Niu

As the suspension bridge structures become more flexible and the forms of the vehicle load become more diverse, the dynamic coupling problem of the vehicle-bridge system has become gradually prominent in long-span suspension bridges, resulting in an increase in accuracy and efficiency requirements for dynamic coupling analysis of the vehicle-bridge system. Conventional method such as finite element method (FEM) for dynamic coupling analysis of vehicle-bridge system often requires separate iteration of vehicle system and bridge system, and the contact and coupling interactions between them are used as the link for convergence inspection, which is too computationally intensive and time-consuming. In addition, the dynamic response of the vehicle-bridge coupling system obtained by FEM cannot be expressed explicitly, which is not convenient for engineering application. To overcome these drawbacks mentioned above, the backpropagation (BP) neural network technology is proposed to the dynamic coupling analysis of the vehicle-bridge system of long-span suspension bridges. Firstly, the BP neural network was used to approximate the dynamic response of the suspension bridge in the vehicle-bridge coupling system, and the complex finite element analysis results were thus explicitly displayed in the form of a mathematical analytical expression. And then the dynamic response of the suspension bridge under vehicle load was obtained by using a dynamic explicit analysis method. It is shown through a numerical example that, compared with FEM, the proposed method is much more economical to achieve reasonable accuracy when dealing with the dynamic coupling problem of the vehicle-bridge system. Finally, an engineering case involving a detailed finite element model of a long-span suspension bridge with a main span of 1688 m is presented to demonstrate the applicability and efficiency under the premise of ensuring the approximation accuracy, which indicates that the proposed method provides a new approach for dynamic coupling analysis of the vehicle-bridge system of long-span suspension bridges.

2020 ◽  
Vol 10 (21) ◽  
pp. 7666
Author(s):  
Ngoc-Son Dang ◽  
Gi-Tae Rho ◽  
Chang-Su Shim

Long-span suspension bridges require accumulated design and construction technologies owing to challenging environmental conditions and complex engineering practices. Building information modeling (BIM) is a technique used to federate essential data on engineering knowledge regarding cable-supported bridges. In this study, a BIM-based master digital model that uses a data-driven design for multiple purposes is proposed. Information requirements and common data environments are defined considering international BIM standards. A digital inventory for a suspension bridge is created using individual algorithm-based models, and an alignment-based algorithm is used to systematize them and generate the entire bridge system. After assembling the geometrical model, metadata and various BIM applications are linked to create the federated master model, from which the mechanical model is derived for further stages. During the construction stage, the advantage of this digital model lies in its capability to perform efficient revisions and updates with respect to varying situations during the erection process. Stability analyses of the bridge system can be performed continuously at each erection step while considering the geometric control simulation. Furthermore, finite element analysis models for any individual structural member can be extracted from the master digital model, which is aimed at estimating the actual behavior of bridge members. In addition, a pilot master digital model was generated and applied to an existing suspension bridge; this model exhibited significant potential in terms of bridge data generation and manipulation.


2011 ◽  
Vol 243-249 ◽  
pp. 1817-1825
Author(s):  
Jing Qiu ◽  
Rui Li Shen ◽  
Huai Guang Li

As a composite structure, the cable-stayed-suspension bridge is characterized by relatively new structure, great overall stiffness and long-span capacity, which has been proposed for the design of some extra long-span bridges. In order to research further into the mechanics characteristics of this type of structural system, the proposed preliminary design of a cable-stayed-suspension bridge with a main span of 1800m is analyzed by means of finite element simulation method. The advantages on overall stiffness in the cable-stayed-suspension bridge are summarized in comparison with the three-span suspension bridge and the single-span suspension bridge. Then, the reasons for the fatigue of the longest suspension cables in the cable-stayed-suspension bridge are also discussed in this paper.


2014 ◽  
Vol 1030-1032 ◽  
pp. 802-806
Author(s):  
Xu Luo ◽  
Xin Sha Fu ◽  
Li Xiong Gu ◽  
Lu Rong Cai

The cable tower is the bearing component of long-span suspension bridges, and its structure is very high and bear large force, which determines the stability and is the key of safety control. As for the height of the main tower of a long-span suspension bridge up to 195.3 m, the finite element software ANSYS is used to establish a three-dimensional finite element model (FEM), and the effects of geometric nonlinearity and material nonlinearity on the stability of the main tower are analyzed. The calculation results show that geometrical nonlinearity and material defects have significant influence on the main tower stability, and the nonlinear stability should be considered under wind load in the design calculation.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Hongyu Jia ◽  
Kang Jia ◽  
Caizhi Sun ◽  
Yanqiang Li ◽  
Chao Zhang ◽  
...  

AbstractThe objective of this paper is to expediently expose the seismic performance pertinent to demand and capacity of general long-span suspension bridges crossing active faults. Firstly three dimensional finite element model of the ordinary long-span suspension bridge is established based on the powerful and attractive finite element software ANSYS. Secondly a series of appropriate fault ground motions with different target final permanent displacements (Tectonic displacements or ground offset) in the direction perpendicular to the fault plane are assumed and applied to the employed long-span suspension bridge. And then the Newmark method is utilized to solve the equation of motion of the long-span suspension bridge structure subjected to fault ground motions in the elastic range. Finally some important conclusions are drawn that the final permanent displacements in the direction perpendicular to the fault plane has significant influence on the seismic responses and demands of general long-span suspension bridges crossing active faults. And the resultant conclusions deliver explicitly and directly specifications and guidelines for seismic design of ordinary long-span suspension bridges across fault-rupture zones.


2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Chang-ke Jiao ◽  
Xin Dong ◽  
Ai-qun Li ◽  
Guang-dong Zhou ◽  
Xiao-ping Wu

Multitower suspension bridge is of different style compared to the traditional suspension bridge with two towers, and consequently the dissimilarity of static and dynamic behaviors is distinct. As a special case of multitower suspension bridge, two long-span triple-tower suspension bridges have been constructed in China and the seismic random response of triple-tower suspension bridges is studied in this paper. A nonlinear dynamic analysis finite element model is established in ABAQUS and the Python language is utilized to facilitate the preprocess and postprocess during the finite element analysis. The procedure for random response calculation of structures based on the pseudoexcitation method is presented, with the initial equilibrium state of structure considered, which may be ignored for long-span bridges during calculating of stochastic response. The stationary seismic random responses of triple-tower suspension bridge under uniform excitation in firm, medium, and soft soil conditions and under spatially varying excitation in soft soil are investigated. The distribution of RMS of random responses of displacements and internal forces of the stiffening girder and towers is presented and discussed in detail. Results show that spatially variable ground motions should be considered in the stochastic analysis of triple-tower suspension bridge.


2006 ◽  
Vol 11 (3) ◽  
pp. 293-318 ◽  
Author(s):  
M. Zribi ◽  
N. B. Almutairi ◽  
M. Abdel-Rohman

The flexibility and low damping of the long span suspended cables in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck with a constant speed. A vertical cable between the bridge deck and the suspended cables is used to install a hydraulic actuator able to generate an active control force on the bridge deck. Two control schemes are proposed to generate the control force needed to reduce the vertical vibrations in the suspended cables and in the bridge deck. The proposed controllers, whose design is based on Lyapunov theory, guarantee the asymptotic stability of the system. The MATLAB software is used to simulate the performance of the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a velocity feedback controller.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hao Tian ◽  
Jiji Wang ◽  
Sugong Cao ◽  
Yuanli Chen ◽  
Luwei Li

This paper presents a reliability analysis to assess the safety of corroded main cables of a long-span suspension bridge. A multiscale probability model was established for the resistance of the main cables considering the length effect and the Daniels effect. Corrosion effects were considered in the wire scale by relating the test results from accelerated corrosion tests to the corrosion stages and in the cable scale by adopting a corrosion stage distribution of the main cable section in NCHRP Report 534. The load effects of temperature, wind load, and traffic load were obtained by solving a finite element model with inputs from in-service monitoring data. The so-obtained reliability index of the main cables reduces significantly after operation for over 50 years and falls below the design target value due to corrosion effects on the mechanical properties of the steel wire. Multiple measures should be taken to delay the corrosion effects and ensure the safety of the main cables in the design service life.


2018 ◽  
Vol 18 (08) ◽  
pp. 1840009 ◽  
Author(s):  
Hao Wang ◽  
Yifeng Wu ◽  
Ben Sha ◽  
Wenzhi Zheng ◽  
Yuqi Gao

In the design of super-long-span suspension bridges, the floating system is commonly adopted. However, this system may lead to the excessive earthquake-excited longitudinal displacement (LD) at the end of the main girder, which in return could result in pounding damage at expansion joints. In this paper, Taizhou Bridge, the triple-tower suspension bridge with the longest main span in the world, is taken as an example to demonstrate the effectiveness of three different approaches (elastic links, viscous dampers, and their combination) of mitigating the possible excessive LD. The finite element code ABAQUS is used to build the numerical model of the bridge and calculate the dynamic characteristics as well as the seismic responses. Then, 24 cases with different parameters of elastic links and viscous dampers are investigated and it is observed that the mitigation effect of the 24 cases varies significantly with different parameters. To obtain the optimized mitigation effect for seismic responses, including the LD of the girder, the LD and shear force of all towers, in the 24 cases, the modified analytic hierarchy process (AHP) method is introduced to realize the compositive optimal control of the triple-tower suspension bridge. Results show that the 24th case is the optimal one in which the LD of the girder is reduced significantly while the inner force of towers does not get excessive increase.


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