Suppression of Bridge Flutter Using Suction Control

To verify the effectiveness of the suction-based method for improving flutter stability of long-span bridges, the forced vibration experiments for extracting the flutter derivatives of a section model with and without suction were performed, and the corresponding critical flutter wind speeds of this structure were calculated out. It is shown by the experiment that the flutter stability of the bridge depends on suction configuration. As the suction holes locate at the leeward side of the model, the critical flutter wind speed can attain maximum under the same suction velocity. In the analytical results, it is remarkably effective that the suction control improves the long-span bridge flutter stability.

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Numerical Simulation of Wind-Driven Rain on a Long-Span Bridge

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455419501499 ◽

2019 ◽

Vol 19 (12) ◽

pp. 1950149

Author(s):

Shenghong Huang ◽

Qiusheng Li ◽

Man Liu ◽

Fubin Chen ◽

Shun Liu

Keyword(s):

Numerical Simulation ◽

Wind Engineering ◽

Multiphase Model ◽

Rain Intensity ◽

Long Span Bridges ◽

Long Span ◽

Long Span Bridge ◽

Extreme Rain ◽

Section Model ◽

Bridge Spans

Wind-driven rain (WDR) and its interactions with structures is an important research subject in wind engineering. As bridge spans are becoming longer and longer, the effects of WDR on long-span bridges should be well understood. Therefore, this paper presents a comprehensive numerical simulation study of WDR on a full-scale long-span bridge under extreme conditions. A validation study shows that the predictions of WDR on a bridge section model agree with experimental results, validating the applicability of the WDR simulation approach based on the Eulerian multiphase model. Furthermore, a detailed numerical simulation of WDR on a long-span bridge, North Bridge of Xiazhang Cross-sea Bridge is conducted. The simulation results indicate that although the loads induced by raindrops on the bridge surfaces are very small as compared to the wind loads, extreme rain intensity may occur on some windward surfaces of the bridge. The adopted numerical methods and rain loading models are validated to be an effective tool for WDR simulation for bridges and the results presented in this paper provide useful information for the water-erosion proof design of future long-span bridges.

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Feasibility Study of Super-Long Span Bridges Considering Aerostatic Instability by a Two-Stage Geometric Nonlinear Analysis

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455421500334 ◽

2020 ◽

pp. 2150033

Author(s):

Jiunn-Yin Tsay

Keyword(s):

Wind Speed ◽

Nonlinear Analysis ◽

Two Stage ◽

Long Span Bridges ◽

Critical Wind Speed ◽

Long Span ◽

Main Cable ◽

Geometric Nonlinear ◽

Long Span Bridge ◽

Geometric Nonlinear Analysis

To meet the need of constructing fixed cross strait links, super-long span bridge with a main span over 2 000[Formula: see text]m is considered as a candidate for their ability to cross deep and wide straits. To this end, some super-long span bridges with proper cable and girder systems were previously proposed and studied. The major design considerations are aimed at adopting new cable material, increasing the entire rigidity of the bridge, stabilizing the dynamic characteristics, strengthening the deck sections, etc. In this paper, a brief review of main cable and girder system is first given of the concepts previously proposed for the design of super-long span bridges. Then some typical examples are studied, focused on various issues related to the design of super-long span bridges, including composite cable, the unstressed length and tension force of the main cable, the stiffness and mass effects of the deck on critical wind speed, and the critical wind speed of various cable systems. The most challenges in super-long span bridges are to solve aerostatic and aerodynamic instability at required design wind speed. In this connection, the wind-induced aerostatic instability of super-long span bridges is studied by a two-stage geometric nonlinear analysis for dead loads and wind loads. The developed program adopted herein for geometric nonlinear analysis was verified and confirmed before. The proposed methods (i.e. composite cable, slotted girder, increasing deck stiffness and mass, cable layout, etc.) obtained for all the examples are in agreement with this study, which indicates applicability of the design approaches presented.

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Steady-Suction-Based Flow Control of Flutter of Long-Span Bridge

Applied Sciences ◽

10.3390/app10041372 ◽

2020 ◽

Vol 10 (4) ◽

pp. 1372

Author(s):

Jian Zhan ◽

Hongfu Zhang ◽

Zhiwen Liu ◽

Huan Liu ◽

Dabo Xin ◽

...

Keyword(s):

Flow Control ◽

Bridge Deck ◽

Control Method ◽

Control Device ◽

Maximal Increase ◽

Long Span ◽

Suction Control ◽

Long Span Bridge ◽

Bridge Model ◽

Section Model

The present wind tunnel study focuses on the effects of the steady-suction-based flow control method on the flutter performance of a 2DOF bridge deck section model. The suction applied to the bridge model was released from slots located at the girder bottom. The suction rates of all slots along the span were equal and constant. A series of test cases with different combinations of suction slot positions, suction intervals, and suction rates were studied in detail for the bridge deck model. The experimental results showed that the steady-suction-based flow control method could improve the flutter characteristics of the bridge deck with a maximal increase in the critical flutter speed of up to 10.5%. In addition, the flutter derivatives (FDs) of the bridge deck with or without control were compared to investigate the fundamental mechanisms of the steady-suction-based control method. According to the results, installing a suction control device helps to strengthen aerodynamic damping, which is the primary cause for enhanced flutter performance of bridge decks.

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.105-107.9 ◽

2011 ◽

Vol 105-107 ◽

pp. 9-12 ◽

Cited By ~ 2

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.

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A predictive critical flutter wind speed modeling for long-span bridges

Advances in Structural Engineering ◽

10.1177/1369433219900977 ◽

2020 ◽

Vol 23 (9) ◽

pp. 1823-1837

Author(s):

Kun Lin ◽

Minghai Wei ◽

Hongjun Liu ◽

Huafeng Wang

Keyword(s):

Wind Speed ◽

Wind Tunnel ◽

Dimensional Space ◽

Three Dimensional ◽

Wind Tunnel Tests ◽

Long Span Bridges ◽

Wind Speeds ◽

Long Span ◽

Aerodynamic Model ◽

Proposed Model

In this article, a two-dimensional Lighthill aerodynamic model is first extended to three-dimensional space, and then combined with the larger Von Karman plate deformation theory, a model for predicting the critical flutter wind speeds of long-span bridges in the primary design is proposed. The predictions of the presented model are compared to the results of wind tunnel tests for five long-span bridges with different main girder section forms. After that, based on the proposed model, the effects of width to span ratio and thickness to span ratio on the critical flutter wind speeds of long-span bridges are investigated. The results show that the differences between the proposed model and wind tunnel tests are only 7%–14%. Therefore, the presented model can assess the flutter wind speed in preliminary design stages of a bridge. The results also reveal that width to span ratios between 1/30 and 1/10 and thickness to span ratios between 1/300 and 1/100 are optimal for long-span bridges.

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Design Wind Speed Estimation for Long Span Bridges in Korean Southern and Western Coasts

International Journal of Engineering and Technology Innovation ◽

10.46604/ijeti.2020.3545 ◽

2020 ◽

Vol 10 (2) ◽

pp. 146-155

Author(s):

Dooyong Cho

Keyword(s):

Wind Speed ◽

Least Squares ◽

Return Period ◽

Least Squares Method ◽

Wind Load ◽

Suspension Bridges ◽

Method Of Moment ◽

Long Span Bridges ◽

Wind Speeds ◽

Long Span

Recently, many long-span cable supported bridges, including the cable stayed bridges and the suspension bridges, have already been constructed or are planned for construction. Because the meteorological values used to estimate the wind load for designing the long-span bridges were based on data from the 1960s through 1995 in Korea, it is necessary to reconsider the proper design wind load for long-span bridges. In this paper, the research area is confined to the southern and western coasts of Korea where many long-span bridges have been built. The method of moment and the least-squares method are used to estimate the expected wind speeds of a 100-year return period for girder bridges; Gumbel’s distribution is used to estimate the expected wind speeds of a 200-year return period for long-span bridges. As the return period wind speed on the land surface is revised because of recent high-speed velocity, the revised return period wind speed is increased by 17%. The compatibility of return period wind speed is also evaluated using the RMS (root mean square) error method. This paper concludes that the least-squares method is more compatible than the method of moment for the case of the southern and western coasts of Korea.

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Super-long span bridge aerodynamics: on-going results of the TG3.1 benchmark test – Step 1.2

IABSE Congress, New York, New York 2019: The Evolving Metropolis ◽

10.2749/newyork.2019.2644 ◽

2019 ◽

Author(s):

Giorgio Diana ◽

Stoyan Stoyanoff ◽

Andrew Allsop ◽

Luca Amerio ◽

Tommaso Argentini ◽

...

Keyword(s):

Numerical Models ◽

Experimental Tests ◽

Numerical Comparison ◽

Aeroelastic Stability ◽

Turbulent Wind ◽

Long Span Bridges ◽

Buffeting Response ◽

Long Span ◽

Long Span Bridge ◽

Sectional Model

<p>This paper is part of a series of publications aimed at the divulgation of the results of the 3-step benchmark proposed by the IABSE Task Group 3.1 to define reference results for the validation of the software that simulate the aeroelastic stability and the response to the turbulent wind of super-long span bridges. Step 1 is a numerical comparison of different numerical models both a sectional model (Step 1.1) and a full bridge (Step 1.2) are studied. Step 2 will be the comparison of predicted results and experimental tests in wind tunnel. Step 3 will be a comparison against full scale measurements.</p><p>The results of Step 1.1 related to the response of a sectional model were presented to the last IABSE Symposium in Nantes 2018. In this paper, the results of Step 1.2 related to the response long-span full bridge are presented in this paper both in terms of aeroelastic stability and buffeting response, comparing the results coming from several TG members.</p>

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Influence of Wind Speed, Wind Direction and Turbulence Model for Bridge Hanger: A Case Study

Symmetry ◽

10.3390/sym13091633 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1633

Author(s):

Yang Ding ◽

Shuang-Xi Zhou ◽

Yong-Qi Wei ◽

Tong-Lin Yang ◽

Jing-Liang Dong

Keyword(s):

Wind Speed ◽

Wind Direction ◽

Wind Field ◽

Solid Mechanics ◽

Von Mises Stress ◽

Long Span Bridges ◽

High Rise ◽

Long Span ◽

Cfd Models ◽

Von Mises

Wind field (e.g., wind speed and wind direction) has the characteristics of randomness, nonlinearity, and uncertainty, which can be critical and even destructive on a long-span bridge’s hangers, such as vortex shedding, galloping, and flutter. Nowadays, the finite element method is widely used for model calculation, such as in long-span bridges and high-rise buildings. In this study, the investigated bridge hanger model was established by COMSOL Multiphysics software, which can calculate fluid dynamics (CFD), solid mechanics, and fluid–solid coupling. Regarding the wind field of bridge hangers, the influence of CFD models, wind speed, and wind direction are investigated. Specifically, the bridge hanger structure has symmetrical characteristics, which can greatly reduce the calculation efficiency. Furthermore, the von Mises stress of bridge hangers is calculated based on fluid–solid coupling.

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