scholarly journals Ensuring the aerodynamic stability of the long-span bridges through studies in the wind tunnel

2018 ◽  
Vol 245 ◽  
pp. 02001 ◽  
Author(s):  
Evgenii Khrapunov ◽  
Sergei Solovev
Keyword(s):  
Wind Tunnel ◽  
Design Process ◽  
Aerodynamic Characteristics ◽  
Elastic Instability ◽  
Experimental Facility ◽  
Bridge Design ◽  
Aerodynamic Stability ◽  
Long Span Bridges ◽  
Long Span ◽  
Main Ideas

The main ideas of the aerodynamic studies of large bridges are presented in present paper. Main types of aero-elastic instability for bridges with spans over 100 meters are considered. A two-step modeling approach is presented. At the first stage, the aerodynamic characteristics of the span fragment are considered, at the second.stage the characteristics of the whole bridge. Methods for investigation of bridge oscillations in a special-purpose experimental facility – the Landscape Wind Tunnel – are described. Examples of tests with elastic similar models of bridges are given, and measurements to mitigate dangerous oscillations early in the bridge design process are described.

scholarly journals Wind-Induced Phenomena in Long-Span Cable-Supported Bridges: A Comparative Review of Wind Tunnel Tests and Computational Fluid Dynamics Modelling

2021 ◽  
Vol 11 (4) ◽  
pp. 1642
Author(s):  
Yuxiang Zhang ◽  
Philip Cardiff ◽  
Jennifer Keenahan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
Careful Analysis ◽  
Wind Effects ◽  
Wind Tunnel Tests ◽  
Long Span Bridges ◽  
Long Span ◽  
Comparative Review ◽  
Dynamics Modelling

Engineers, architects, planners and designers must carefully consider the effects of wind in their work. Due to their slender and flexible nature, long-span bridges can often experience vibrations due to the wind, and so the careful analysis of wind effects is paramount. Traditionally, wind tunnel tests have been the preferred method of conducting bridge wind analysis. In recent times, owing to improved computational power, computational fluid dynamics simulations are coming to the fore as viable means of analysing wind effects on bridges. The focus of this paper is on long-span cable-supported bridges. Wind issues in long-span cable-supported bridges can include flutter, vortex-induced vibrations and rain–wind-induced vibrations. This paper presents a state-of-the-art review of research on the use of wind tunnel tests and computational fluid dynamics modelling of these wind issues on long-span bridges.

Flutter mitigation of a superlong-span suspension bridge with a double-deck truss girder through wind tunnel tests

2020 ◽  
pp. 107754632094615
Author(s):  
Yanguo Sun ◽  
Yongfu Lei ◽  
Ming Li ◽  
Haili Liao ◽  
Mingshui Li
Keyword(s):  
Wind Tunnel ◽  
Damping Ratio ◽  
Suspension Bridge ◽  
Wind Tunnel Tests ◽  
Long Span Bridges ◽  
Long Span ◽  
Upper Deck ◽  
Torsional Damping ◽  
And Control ◽  
Wind Induced Vibration

As flutter is a very dangerous wind-induced vibration phenomenon, the mitigation and control of flutter are crucial for the design of long-span bridges. In the present study, via a large number of section model wind tunnel tests, the flutter performance of a superlong-span suspension bridge with a double-deck truss girder was studied, and a series of aerodynamic and structural measures were used to mitigate and control its flutter instability. The results show that soft flutter characterized by a lack of an evident divergent point occurred for the double-deck truss girder. Upper central stabilizers on the upper deck, lower stabilizers below the lower deck, and horizontal flaps installed beside the bottoms of the sidewalks are all effective in suppressing flutter for this kind of truss girder. By combining the structural design with aerodynamic optimizations, a redesigned truss girder with widened upper carriers and sidewalks, and double lower stabilizers combined with the inspection vehicle rails is identified as the optimal flutter mitigation scheme. It was also found that the critical flutter wind speed increases with the torsional damping ratio, indicating that the dampers may be efficient in controlling soft flutter characterized by single-degree-of-freedom torsional vibration. This study aims to provide a useful reference and guidance for the flutter design optimization of long-span bridges with double-deck truss girders.

Effect of Turbulence on the Aerodynamic Stability of Long Span Bridges

2013 ◽  
Vol 639-640 ◽  
pp. 452-455 ◽  
Author(s):  
Chun Guang Li ◽  
Zheng Qing Chen ◽  
Zhi Tian Zhang
Keyword(s):  
Wind Tunnel Test ◽  
Grid Turbulence ◽  
Aerodynamic Stability ◽  
Rectangular Section ◽  
Long Span Bridges ◽  
Long Span ◽  
Turbulence Flow ◽  
Turbulence Effect ◽  
Suspended Bridge ◽  
Derivatives Of

The study deals with the problem of turbulence effect on the instability of a long span suspended bridge. Wind tunnel test of three representative section models have been carried out in four type of passive grid turbulence flow to clarify the effect of turbulence intensity and turbulence scales. It was found that the turbulence has little effect on the derivatives of those streamlined deck sections, while it exhibits significant stabilizing effect on the bluff rectangular section prism. The loss of spanwise correlation may not be the main reasons induce the change of flutter stability in turbulence.

Comparative and sensitivity study of flutter derivatives of selected bridge deck sections, Part 2: Implications on the aerodynamic stability of long-span bridges

2009 ◽  
Vol 31 (9) ◽  
pp. 2194-2202 ◽  
Author(s):  
Luca Caracoglia ◽  
Partha P. Sarkar ◽  
Frederick L. Haan ◽  
Hiroshi Sato ◽  
Jun Murakoshi
Keyword(s):  
Bridge Deck ◽  
Sensitivity Study ◽  
Aerodynamic Stability ◽  
Long Span Bridges ◽  
Long Span ◽  
Derivatives Of ◽  
Flutter Derivatives

scholarly journals Aerodynamic study of a suspension bridge deck by CFD simulations, wind tunnel tests and full-scale observations

2021 ◽  
Vol 1201 (1) ◽  
pp. 012007
Author(s):  
I. Kusano ◽  
E. Cheynet ◽  
J. B. Jakobsen ◽  
J. Snæbjörnsson
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Suspension Bridge ◽  
Aerodynamic Characteristics ◽  
Full Scale ◽  
Navier Stokes ◽  
Cfd Simulations ◽  
Wind Tunnel Tests ◽  
Long Span Bridges ◽  
Wide Range

Abstract Assessing the aerodynamic characteristics of long-span bridges is fundamental for their design. Depending on the terrain complexity and local wind conditions, episodes of large angles of attack (AoA) of 15° may be observed. However, such large AoAs ( above 10°) are often overlooked in the design process. This paper studies the aerodynamics properties of a flow around a single-box girder for a wide range of AoAs, from –20° to 20°, using numerical simulations. The simulations are based on a 2D unsteady Reynolds-averaged Navier–Stokes (URANS) approach using the k − ω SST turbulence model with a Reynolds number of 1.6 × 105. Numerically obtained aerodynamic static coefficients were compared to wind tunnel test data. The CFD results were generally in good agreement with the wind tunnel tests, especially for small AoAs and positive AoAs. More discrepancies were observed for large negative AoA, likely due to the limitation of modelling 3D railings with 2D simulations. The simulated velocity deficit downstream of the deck was consistent with the one measured in full-scale using short-range Doppler wind lidar instruments. Finally, the Strouhal number from the CFD simulations were in agreement with the value obtained from the full-scale data.

Wind tunnel: a fundamental tool for long-span bridge design

2020 ◽  
pp. 121-143
Author(s):  
Giorgio Diana ◽  
Daniele Rocchi ◽  
Marco Belloli
Keyword(s):  
Wind Tunnel ◽  
Bridge Design ◽  
Long Span ◽  
Long Span Bridge

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.

Research on Aerodynamic Impacts of Snow on Bridge Decks

2013 ◽  
Vol 774-776 ◽  
pp. 68-72 ◽  
Author(s):  
Qing Song Duan ◽  
Cun Ming Ma ◽  
Bin Xie
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Bridge Decks ◽  
Aerodynamic Characteristics ◽  
Two Phase ◽  
Snow Load ◽  
Long Span Bridges ◽  
Long Span ◽  
Fluid Theory ◽  
Phase Fluid

With the development of economy and technology, many long span bridges have been constructed. However, oversize thickness and long duration of snow on these long span bridges might lead to security issues. The computational fluid dynamics software FLUENT is employed to simulate the snow effect on the bridges. According to the two-phase fluid theory, the relationship between air phase and snow phase is one-way coupling. The corresponding changes of snow load on the bridge deck under the action of strong winds are studied in this paper and the comparative analysis about aerodynamic impacts before and after the snow are conducted as well. According to the results, the snow has notable influence on the aerodynamic characteristics of bridge decks. Keywords: computational fluid dynamics; two-phase fluid theory; snow load; aerodynamics;

Construction of boundary layer wind tunnel for long-span bridges

1992 ◽  
Vol 42 (1-3) ◽  
pp. 885-896 ◽  
Author(s):  
T. Miyata ◽  
H. Yamata ◽  
K. Yokoyama ◽  
T. Kanazaki ◽  
T. Iijima
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Long Span Bridges ◽  
Long Span

Deformability and Aerodynamic Stability as Limits in Long Span Bridges

2001 ◽  
Vol 84 (8) ◽  
pp. 58-65
Author(s):  
Domenico Bruno ◽  
Mario Como ◽  
Antonio Grimaldi ◽  
Angelo Leonardi
Keyword(s):  
Aerodynamic Stability ◽  
Long Span Bridges ◽  
Long Span
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