scholarly journals A Master Digital Model for Suspension Bridges

2020 ◽  
Vol 10 (21) ◽  
pp. 7666
Author(s):  
Ngoc-Son Dang ◽  
Gi-Tae Rho ◽  
Chang-Su Shim
Keyword(s):  
Suspension Bridge ◽  
Geometrical Model ◽  
Information Modeling ◽  
Digital Model ◽  
Suspension Bridges ◽  
Actual Behavior ◽  
Data Generation ◽  
Element Analysis ◽  
Long Span ◽  
Bridge System

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.

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
Keyword(s):  
Neural Network ◽  
Finite Element ◽  
Dynamic Response ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Dynamic Coupling ◽  
Coupling Analysis ◽  
Long Span ◽  
Coupling System ◽  
Bridge System

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.

scholarly journals Seismic Response of Long-Span Triple-Tower Suspension Bridge under Random Ground Motion

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Chang-ke Jiao ◽  
Xin Dong ◽  
Ai-qun Li ◽  
Guang-dong Zhou ◽  
Xiao-ping Wu
Keyword(s):  
Finite Element ◽  
Soft Soil ◽  
Nonlinear Dynamic Analysis ◽  
Suspension Bridge ◽  
Soil Conditions ◽  
Suspension Bridges ◽  
Random Response ◽  
Element Analysis ◽  
Long Span ◽  
Random Responses

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.

A parametric study of long-span triple-tower suspension bridge

2020 ◽  
Vol 23 (15) ◽  
pp. 3185-3194
Author(s):  
Jia Lijun ◽  
Wang Jinliang ◽  
Jiang Yang ◽  
Xu Rong
Keyword(s):  
Parametric Study ◽  
Mechanical Performance ◽  
Structural Parameters ◽  
Beam Width ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Analysis Method ◽  
Element Analysis ◽  
Long Span ◽  
Beam Height

A sufficient understanding of the mechanical performance of long-span triple-tower suspension bridge is essential for practical design as such bridge is significantly different from traditional suspension bridges because of the flexible middle tower. Accordingly, a parametric study of a triple-tower suspension bridge with main span of 2000 m is performed in this article. Based on finite-element analysis method, influences of several structural parameters on mechanical performance are investigated, including connection between tower and girder, ratio of beam height to span and beam width to span, which would provide reference and help for parameter selection in preliminary design.

scholarly journals Analysis of the rainfall influence on critical wind speed of flutter of long-span suspension bridge based on mumerical method

2020 ◽  
Vol 319 ◽  
pp. 07002
Author(s):  
Hu Jun
Keyword(s):  
Wind Speed ◽  
Suspension Bridge ◽  
Movement Speed ◽  
Suspension Bridges ◽  
Mountainous Area ◽  
Element Analysis ◽  
Critical Wind Speed ◽  
Damping Matrix ◽  
Long Span ◽  
The Impact

In order to study the influence of rainfall on the critical wind speed of flutter of long-span suspension bridges in mountainous area, the impact of rainfall on stiffening girder is analyzed based on the main characteristics of rainfall and the movement speed in all directions. The mechanical equation under the joint action of wind and rain is established and the impact force is transferred, the damping effect of rainfall is then derived, and the element damping matrix form of rainfall is obtained by combining the integration of shape function. Furthermore, the flutter motion equation of wind-rain-bridge coupling system is derived, and the finite element analysis method for critical wind speed of structural flutter considering the influence of rainfall is established. Finally, taking a large-span suspension bridge in mountainous area as the research object, the influence of rainfall on the critical wind speed of flutter is analyzed, the results indicate that the critical wind speed of flutter will be accordingly increased due to the existence of rainfall damping, whereas the mass of raindrops is too light and the final velocity of raindrops in the falling process is low, the critical wind speed of flutter increased by only 5.54% in the case of heavy rainstorm. Therefore, when the rainfall intensity is general, the influence of rainfall on the critical wind speed of flutter can be ignored.

Control of Vibrations due to Moving Loads on Suspension Bridges

2006 ◽  
Vol 11 (3) ◽  
pp. 293-318 ◽  
Author(s):  
M. Zribi ◽  
N. B. Almutairi ◽  
M. Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
Lyapunov Theory ◽  
Dynamic Responses ◽  
Suspension Bridges ◽  
Control Force ◽  
Moving Loads ◽  
Hydraulic Actuator ◽  
Long Span ◽  
Suspended Cables

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.

scholarly journals Probabilistic Assessment of the Safety of Main Cables for Long-Span Suspension Bridges considering Corrosion Effects

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hao Tian ◽  
Jiji Wang ◽  
Sugong Cao ◽  
Yuanli Chen ◽  
Luwei Li
Keyword(s):  
Probability Model ◽  
Steel Wire ◽  
Suspension Bridge ◽  
Element Model ◽  
Traffic Load ◽  
Suspension Bridges ◽  
Accelerated Corrosion ◽  
Long Span ◽  
Accelerated Corrosion Tests ◽  
Main Cables

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.

Influence of Temperature and Increasing Traffic Flow on the Fatigue Damage of Welded Bridge Decks

2007 ◽  
Vol 348-349 ◽  
pp. 341-344 ◽  
Author(s):  
Tong Guo ◽  
Ai Qun Li ◽  
Zhao Xia Li
Keyword(s):  
Traffic Flow ◽  
Fatigue Damage ◽  
Suspension Bridge ◽  
Life Assessment ◽  
Element Analysis ◽  
Influence Of Temperature ◽  
Linear Effect ◽  
Long Span ◽  
Traffic Growth ◽  
Using Data

Fatigue life assessment of critical bridge members using online monitoring data has been investigated in recent years. To make a quick and efficient evaluation, a representative block of strain cycles is usually defined. However, such block sometimes fails to cover the change in fatigue damage by temperature fluctuation and traffic growth, which is important to the life prediction of the welds in a long-span suspension bridge. To find the influence of temperature and traffic volume on the fatigue damage, an equivalent vehicle load method is dedicated through finite element analysis, and the statistical disposition of traffic flow has been conducted, using data from the Runyang Bridge. The influence of traffic growth can be estimated and eliminated from the total damage so that the temperature effect on the fatigue damage is finally obtained. It is found that temperature has a linear effect on the fatigue damage. According to the fitted relationship between fatigue damage, temperature and the traffic flow, a more objective fatigue assessment is undertaken, based on the rain-flow counting method and the Palgren-Miner rule.

Compositive Optimal Control for the Seismic Response of a Long-Span Triple-Tower Suspension Bridge

2018 ◽  
Vol 18 (08) ◽  
pp. 1840009 ◽  
Author(s):  
Hao Wang ◽  
Yifeng Wu ◽  
Ben Sha ◽  
Wenzhi Zheng ◽  
Yuqi Gao
Keyword(s):  
Optimal Control ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Seismic Responses ◽  
Viscous Dampers ◽  
Analytic Hierarchy ◽  
Expansion Joints ◽  
Elastic Links ◽  
Long Span ◽  
Floating System

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.

Wind Tunnel Studyon Vortex-Induced Vibration Characteristics of Long-Span Suspension Bridges with Single Cable Plane

2014 ◽  
Vol 633-634 ◽  
pp. 1263-1266
Author(s):  
Huang Yu
Keyword(s):  
Wind Tunnel ◽  
Suspension Bridge ◽  
Wind Tunnel Experiment ◽  
Vibration Characteristics ◽  
Torsional Stiffness ◽  
Suspension Bridges ◽  
Vortex Induced Vibration ◽  
Long Span Bridges ◽  
Wind Speeds ◽  
Long Span

For modern long-span bridges, both the optimization of aerodynamic shape and the increase of torsional stiffness according to the result of the wind tunnel experiment could avoid the flutter instability.Vortex-inducedvibration with relatively large amplitude happens easily at low wind speeds. In this paper, based on wind tunnel experiment, by studying on the vortex-induced vibration characteristics of a long-span suspension bridge with single cable plane, aerodynamic measures for easing the vortex-induced vibration are given.

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