scholarly journals Multiobjective Optimal Control of Longitudinal Seismic Response of a Multitower Cable-Stayed Bridge

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Geng Fangfang ◽  
Ding Youliang
Keyword(s):  
Multiobjective Optimization ◽  
Viscous Fluid ◽  
Optimization Design ◽  
Bridge Deck ◽  
Design Method ◽  
Constraint System ◽  
Cable Stayed Bridge ◽  
Base Forces ◽  
Fluid Dampers ◽  
Viscous Fluid Dampers

The dynamic behavior of a multitower cable-stayed bridge with the application of partially longitudinal constraint system using viscous fluid dampers under real earthquake ground motions is presented. The study is based on the dynamic finite element model of the Jiashao Bridge, a six-tower cable-stayed bridge in China. The prime aim of the study is to investigate the effectiveness of viscous fluid dampers on the longitudinal seismic responses of the bridge and put forth a multiobjective optimization design method to determine the optimized parameters of the viscous fluid dampers. The results of the investigations show that the control objective of the multitower cable-stayed bridge with the partially longitudinal constraint system is to yield maximum reductions in the base forces of bridge towers longitudinally restricted with the bridge deck, with slight increases in the base forces of bridge towers longitudinally unrestricted with the bridge deck. To this end, a multiobjective optimization design method that uses a nondominating sort genetic algorithm II (NSGA-II) is used to optimize parameters of the viscous fluid dampers. The effectiveness of the proposed optimization design method is demonstrated for the multitower cable-stayed bridge with the partially longitudinal constraint system, which reveals that a design engineer can choose a set of proper parameters of the viscous fluid dampers from Pareto optimal fronts that can satisfy the desired performance requirements.

scholarly journals Passive Control System for Mitigation of Longitudinal Buffeting Responses of a Six-Tower Cable-Stayed Bridge

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
Fangfang Geng ◽  
Youliang Ding ◽  
Aiqun Li
Keyword(s):  
Viscous Fluid ◽  
Optimization Design ◽  
Passive Control ◽  
Bridge Deck ◽  
Design Method ◽  
Nsga Ii ◽  
Cable Stayed Bridge ◽  
Base Forces ◽  
Fluid Dampers ◽  
Viscous Fluid Dampers

This paper presents an investigation of mitigation of longitudinal buffeting responses of the Jiashao Bridge, the longest multispan cable-stayed bridge in the world. A time-domain procedure for analyzing buffeting responses of the bridge is implemented in ANSYS with the aeroelastic effect included. The characteristics of longitudinal buffeting responses of the six-tower cable-stayed bridge are studied in some detail, focusing on the effects of insufficient longitudinal stiffness of central towers and partially longitudinal constraints between the bridge deck and part of bridge towers. The effectiveness of viscous fluid dampers on the mitigation of longitudinal buffeting responses of the bridge is further investigated and a multiobjective optimization design method that uses a nondominating sort genetic algorithm II (NSGA-II) is used to optimize parameters of the viscous fluid dampers. The results of the parametric investigations show that, by appropriate use of viscous fluid dampers, the top displacements of central towers and base forces of bridge towers longitudinally restricted with the bridge deck can be reduced significantly, with hampering the significant gain achieved in the base forces of bridge towers longitudinally unrestricted with the bridge deck. And the optimized parameters for the viscous fluid dampers can be determined from Pareto-optimal fronts using the NSGA-II that can satisfy the desired performance requirements.

Speedy Design Method for Fluid Viscous Dampers Based on Numerical Simulation by CFD

2012 ◽  
Vol 446-449 ◽  
pp. 3869-3874
Author(s):  
Qiang Guo ◽  
Yan Bei Chen ◽  
Xiang Liang Ning ◽  
Lu Tang
Keyword(s):  
Numerical Simulation ◽  
Viscous Fluid ◽  
Numerical Method ◽  
Power Law ◽  
Silicone Oil ◽  
Design Method ◽  
Viscous Dampers ◽  
Damping Force ◽  
Fluid Dampers ◽  
Viscous Fluid Dampers

Bi-directional-cylinder viscous fluid dampers are studied numerically. Based on the power-law characteristic of silicone oil，the flow pattern of silicone oil is analyzed, the non-Newtonian fluid power-law model’s influence on the energy dissipation characteristic and the damping resistance of viscous dampers is discussed, and the calculation formulas are presented. The damping force of the viscous damper samples is simulated by professional CFD software based on the dynamic mesh model, Based on comprehensive analysis of the results, the experiential design method of large-tonnage-damping-force viscous fluid dampers is finally established. On the other hand, the numerical simulation curves are in good agreement with experimental curves, which validates the feasibility of numerical method in the preliminary design of bi-directional-cylinder viscous fluid dampers. The numerical method helps to enhance the engineering precision, guide the design, and shorten the development cycle.

Research on the anti-cracking ability of large composite girder cable- stayed bridge

2019 ◽  
Author(s):  
Yuhao Huang ◽  
Liu Chao ◽  
Xu Dong
Keyword(s):  
Principal Stress ◽  
Bridge Deck ◽  
Design Method ◽  
Concrete Bridge ◽  
Cable Stayed Bridge ◽  
Composite Girder ◽  
Concrete Bridge Deck ◽  
Bottom Slab ◽  
First Time ◽  
Bridge Tower

<p>Recently, composite girder cable-stayed bridge is widely used in the world. Since the existing design method takes less focus on the principal stress of the top and bottom slab, the cracking problem of the concrete bridge deck has not been solved perfectly yet. Based on the spatial grid model, this paper takes Guan He Bridge in Jiangsu province as an example to analyze this kind of structure. Monitoring the principal stress of the concrete bridge deck is proposed for the first time to study the effect of diagonal crack. The principal stress of the concrete deck in the middle span, the quartile span, one-eighth of the span, the side span, the bridge tower, and the auxiliary pier are observed respectively. Comparing the theoretical values with the measured value, the results show that the actual stress state of the whole concrete bridge deck during construction is in accordance with the theoretical calculation. For composite girder cable-stayed bridge, the concrete bridge deck is prone to crack, so it is very significant to control the quality in the construction stage, which can provide a guarantee for the safety and durability of the structure.</p>

Research on Seismic Response Vibration Hybrid Control of Hefei TV Tower

2011 ◽  
Vol 243-249 ◽  
pp. 5197-5203
Author(s):  
Zhi Qiang Zhang ◽  
Fei Ma
Keyword(s):  
Viscous Fluid ◽  
Seismic Response ◽  
Control Method ◽  
Hybrid Control ◽  
Spectral Characteristics ◽  
Vibration Reduction ◽  
Tuned Mass Damper ◽  
Mass Damper ◽  
Fluid Dampers ◽  
Viscous Fluid Dampers

In this paper, Hefei TV Tower is used as an analytical case to examine the Hybrid control method on seismic response. Firstly, on the basis of the other’s work, a bi-model dynamic model is proposed to study the seismic response vibration hybrid control, using tuned mass damper and viscous fluid dampers. Then the optimal coefficient is obtained by considered the seismic response of upper turret as optimization objectives. According to analysis, it’s showed that the seismic responses of the tower are decreased greatly with tuned mass damper and viscous fluid dampers, and the vibration reduction effectiveness of the tower is sensitive to the spectral characteristics of earthquake wave.

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