scholarly journals Effect of the time delay on the magnitude of the onset galloping wind speed in semiactive controlled suspension bridges

2021 ◽  
Vol 9 (3B) ◽  
Author(s):  
Mohamed Abdel-Rohman ◽  
Keyword(s):  
Time Delay ◽  
Wind Speed ◽  
Active Control ◽  
Progressive Collapse ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Semiactive Control ◽  
Control Mechanisms ◽  
Control Force ◽  
Wind Speeds

To increase the onset galloping wind speed, after which galloping of the flexible suspension bridges occurs, resulting in the failure of these bridges due to wind, semiactive control mechanisms could be installed in the bridge to increase its damping. The time delay in processing the active control force and the actuator’s dynamics are, however, major practical problems, which may affect the dynamic stability of the semiactive controlled structure. This paper shows the effect of the time delay on the magnitude of the onset galloping wind speed for a suspension bridge controlled by a semiactive control mechanism. It is shown that the time delay decreases the magnitude of the onset galloping wind speed. This makes the suspended cables in the suspension bridge susceptible for galloping, which may cause progressive collapse for the bridge at low mean wind speeds. This could be avoided if the active control force is designed considering the time delay effect.

Design of a Simple Controller to Control Suspension Bridge Non-linear Vibrations due to Moving Loads

2005 ◽  
Vol 11 (7) ◽  
pp. 867-885 ◽  
Author(s):  
M. Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Control Mechanisms ◽  
Control Force ◽  
Moving Loads ◽  
Non Linear ◽  
Linear Vibrations ◽  
Suspended Cables ◽  
Non Linear System

The flexibility and low damping of the long span suspended cables in suspension bridges make them prone to non-linear vibrations due to wind and moving loads. In this paper we consider the dynamic response of a suspension bridge due to a vertical load moving with a constant speed on the bridge deck. Control mechanisms are suggested to generate control forces to control the non-linear vibrations in the bridge deck and the suspended cables. A simple design is presented for the controller based on the feedback of the velocity measurements taken at the control force location. The design is made first on a linear model before applying it to the actual non-linear system. The method is applied on three different types of control mechanisms. Comparison between the controlled responses using the three controllers indicates that, in addition to the method of designing the control actions, the feasibility of the active control depends mainly on the type of the control mechanism.

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.

Vibration control of suspension bridge due to vertical ground motions

2020 ◽  
Vol 23 (12) ◽  
pp. 2626-2641
Author(s):  
Seyed Hossein Hosseini Lavasani ◽  
Hamed Alizadeh ◽  
Rouzbeh Doroudi ◽  
Peyman Homami
Keyword(s):  
Active Control ◽  
Passive Control ◽  
Ground Motions ◽  
Tuned Mass Damper ◽  
Suspension Bridges ◽  
Control Force ◽  
Wide Range ◽  
Mass Damper

Suspension bridges due to their long span can experience large displacement response under dynamic loading like earthquakes. Unlike other structures, their vertical vibration may make remarkable difficulty that a control strategy seems to be essential. Tuned mass damper is a passive control system that can be changed to active one by adding an external source producing the active control force called active tuned mass damper. Unlike passive systems, active ones need a controller system affecting the performance of them considerably. In this study, the efficiency of tuned mass damper and active tuned mass damper are investigated in the bridges. Two controllers, fuzzy type 2 and fuzzy type 1, are used to estimate control force of active tuned mass damper. Tuned mass damper’s parameters are optimized under wide range of ground motions. Also, fuzzy type 2 and fuzzy type 1’s parameters are optimized under the influence of three different conditions containing far-field and near-field ground motions and also combination of them. In addition, Lion Pride Optimization Algorithm is selected for optimizing section. Numerical analysis indicates that active tuned mass damper is more effective than tuned mass damper, and also active tuned mass damper does not make any instability matter of concern in active control systems. Furthermore, performance of fuzzy type 2 is better than fuzzy type 1.

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.

Study on Wind Resistance of Suspension Bridge with Composite Beam

2012 ◽  
Vol 433-440 ◽  
pp. 705-708
Author(s):  
Xiao Jun Ning ◽  
Qiang Zhao
Keyword(s):  
Wind Speed ◽  
Composite Beam ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Wind Resistance

It is very important that how to improve wind resistance of bridge when design suspension bridge. In this thesis, main wind disaster of suspension bridges is recommended, and summarizes the historical lessons. For the particularity of suspension bridge with composite beam, some suggestions on how to heighten flutter wind speed are suggested.

The Influence of Turbulence Integral Scale to Buffeting of Long-Span Bridge

2011 ◽  
Vol 105-107 ◽  
pp. 9-12 ◽  
Author(s):  
Yi Qing Xiao ◽  
Gang Hu ◽  
Meng Qi Tu ◽  
Rui Qi Zheng
Keyword(s):  
Wind Speed ◽  
Suspension Bridge ◽  
Numerical Results ◽  
Integral Scale ◽  
Wind Speeds ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Integral Scales ◽  
Long Span Bridge ◽  
Peak Value

In this paper, the influence of turbulence integral scale to buffeting responses of long-span bridge is analyzed by adopting 2-D buffeting theory. One cable-stayed bridge and one suspension bridge are selected as analysis object. Buffeting responses are calculated under two different wind speeds and different size of turbulence integral scales, which range from 10m to 80m in this paper. The numerical results show that buffeting responses do not change with turbulence integral scale linearly and when turbulence integral scale increases to one value, buffeting responses reach a peak. In addition, turbulence integral scale corresponding to peak value of buffeting responses rise with growth of wind speed.

Aerodynamic Oscillations in Suspension Bridges

1948 ◽  
Vol 15 (2) ◽  
pp. 151-159
Author(s):  
Edmund Pinney
Keyword(s):  
Suspension Bridge ◽  
Wind Tunnels ◽  
Suspension Bridges ◽  
Wind Speeds ◽  
The Subject ◽  
Tacoma Narrows Bridge ◽  
Adequate Data

Abstract Following the failure in 1940 of the Tacoma Narrows suspension bridge by wind-driven oscillations, the need for developing in advance adequate data concerning wind speeds at which such oscillations occur became apparent. Numerous studies and experiments were undertaken on the subject, the present paper dealing with a symmetrical suspension bridge having two towers in which both sidespan and tower effects are considered. A modification is given to include the effects of roadbed “slats,” and a method is outlined for obtaining flutter speeds from roadbed section models which may fit into standard wind tunnels. The theory is applied to the Tacoma Narrows Bridge.

Optimization of PID controller parameters for active control of single degree of freedom structures

2019 ◽  
Vol 5 (4) ◽  
pp. 130
Author(s):  
Serdar Ulusoy ◽  
Sinan Melih Niğdeli ◽  
Gebrail Bekdaş
Keyword(s):  
Time Delay ◽  
Active Control ◽  
Pid Controller ◽  
Structural Model ◽  
Degree Of Freedom ◽  
Control Force ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Near Fault ◽  
Optimum Parameters

In active control of structures, the parameters of controllers used application must be perfectly tuned. In that case, a good vibration reduction performance can be obtained without a stability problem. During the tuning process, the limit of control force and time delay of controller system must be considered for applicable design. In the study, the optimum parameters of Proportional-Derivative-Integral (PID) type controllers that are proportional gain (K), integral time (Ti) and derivative time (Td) were optimized by using teaching learning-based optimization (TLBO). TLBO is a metaheuristic algorithm imitating the teaching and learning phases of education in classroom. The optimization was done according to the responses of the structure under a directivity pulse of near fault ground motions. In the study, time delay was considered as 20 ms and the optimum parameters of PID controller for a single degree of freedom (SDOF) structural model was found for different control force limits. The performances and feasibility of the method were evaluated by using sets of near fault earthquake records.

scholarly journals Lyapunov-Based Control for Suppression of Wind-Induced Galloping in Suspension Bridges

2011 ◽  
Vol 2011 ◽  
pp. 1-23 ◽  
Author(s):  
Naif B. Almutairi ◽  
Mohamed Zribi ◽  
Mohamed Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
High Amplitude ◽  
Tuned Mass Damper ◽  
Suspension Bridges ◽  
Control Force ◽  
Controlled System ◽  
Mass Damper ◽  
Suspended Cables ◽  
Simulation Results

This paper investigates the suppression of galloping in a suspension bridge due to wind loads. The galloping phenomenon can be destructive due to the high-amplitude oscillations of the structure. Two controllers are proposed to generate the control force needed to suppress the vertical galloping in the suspended cables and in the bridge deck. SIMULINK software is used to simulate 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 tuned mass damper.

An Algorithm for Parameter Identifications of Active Mass Damper and Primary Systems Based on Acceleration Measurements

2017 ◽  
Author(s):  
Chang-Ching Chang ◽  
Jer-Fu Wang ◽  
Chi-Chang Lin
Keyword(s):  
Time Delay ◽  
State Space ◽  
Active Control ◽  
Dynamic Properties ◽  
Feedback Gain ◽  
Control Force ◽  
Theoretical Derivation ◽  
Active Mass ◽  
Mass Damper ◽  
Active Mass Damper

Active control systems have already been installed in real structures and are able to decrease the wind- and earthquake-induced responses, while the active mass damper (AMD) is one of the most popular types of such systems. In practice, an AMD is generally assembled in-situ along with the construction of a building. In such a case, the AMD and the building is coupled as an entire system. After the construction is completed, the dynamic properties of the AMD subsystem and the primary building itself are unknown and cannot be identified individually to verify their design demands. For this purpose, a methodology is developed to obtain the feedback gain of the AMD controller and the dynamic properties of the primary building based on the complex eigen-parameters of the coupled building-AMD system. By means of the theoretical derivation in state-space, the non-classical damping feature of the system is characterized. This methodology can be combined with any state-space based system identification technique as a procedure to achieve the goal on the basis of the acceleration measurements of the building-AMD system. Results from numerical verifications show that the procedure is capable of extracting parameters and is applicable for AMD implementation practices. In addition, control force execution time delay cannot be avoided in real application of active control. Small delay time can degrade the control performance and may cause system instability. In this study, time delay effect of AMD system is considered in the proposed methodology to obtain the feedback gain of the AMD controller and the dynamic properties of the primary building.

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