• Title, Summary, Keyword: bridge aerodynamics

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A coupled wind-vehicle-bridge system and its applications: a review

  • Cai, C.S.;Hu, Jiexuan;Chen, Suren;Han, Yan;Zhang, Wei;Kong, Xuan
    • Wind and Structures
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    • v.20 no.2
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    • pp.117-142
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    • 2015
  • The performance of bridges under strong wind and traffic is of great importance to set the traveling speed limit or to make operational decisions for severe weather, such as controlling traffic or even closing the bridge. Meanwhile, the vehicle's safety is highly concerned when it is running on bridges or highways under strong wind. During the past two decades, researchers have made significant contributions to the simulation of the wind-vehicle-bridge system and their interactive effects. This paper aims to provide a comprehensive review of the overall performance of the bridge and traffic system under strong wind, including bridge structures and vehicles, and the associated mitigation efforts.

Numerical simulation of the effect of section details and partial streamlining on the aerodynamics of bridge decks

  • Bruno, L.;Khris, S.;Marcillat, J.
    • Wind and Structures
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    • v.4 no.4
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    • pp.315-332
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    • 2001
  • Presented herein is a numerical study for evaluating the aerodynamic behaviour of equipped bridge deck sections. In the first part, the method adopted is described, in particular concerning turbulence models, meshing requirements and numerical approach. The validation of the procedure represents the aim of the second part of the paper: the results of the numerical simulation in case of two-dimensional, steady, incompressible, turbulent flow around a realistic bridge deck are compared to the data collected from wind-tunnel tests. In order to demonstrate the influence of the section details and of the partial streamlining of the deck geometry on its aerodynamic behaviour, in the third part of the paper the effect of the fairings and of each item of equipment of the section (such as central barriers, side railings and sidewalks) is evaluated. The study has been applied to the deck section of the Normandy cable-stayed bridge.

Aeroelastic analysis of bridges using FEM and moving grids

  • Selvam, R. Panneer;Govindaswamy, S.;Bosch, Harold
    • Wind and Structures
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    • v.5 no.2_3_4
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    • pp.257-266
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    • 2002
  • In the recent years flow around bridges are investigated using computer modeling. Selvam (1998), Selvam and Bosch (1999), Frandsen and McRobie (1999) used finite element procedures. Larsen and Walther (1997) used discrete vorticity procedure. The aeroelastic instability is a major criterion to be checked for long span bridges. If the wind speed experienced by a bridge is greater than the critical wind speed for flutter, then the bridge fails due to aeroelastic instability. Larsen and Walther (1997) computed the critical velocity for flutter using discrete vortex method similar to wind tunnel procedures. In this work, the critical velocity for flutter will be calculated directly (free oscillation procedure) similar to the approaches reported by Selvam et al. (1998). It is expected that the computational time required to compute the critical velocity using this approach may be much shorter than the traditional approach. The computed critical flutter velocity of 69 m/s is in reasonable comparison with wind tunnel measurement. The no flutter and flutter conditions are illustrated using the bridge response in time.

Recent topics on bridge aerodynamics

  • Matsumoto, Masaru;Shirato, Hiromichi;Yagi, Tomomi
    • Wind and Structures
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    • v.3 no.4
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    • pp.267-277
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    • 2000
  • This paper aims to describe the aerodynamic vibrations of various structural elements of bridges, which are particular issues at present. The aerodynamic countermeasures for those vibrations are also discussed considering the generation mechanisms of the aerodynamic instabilities. In this paper, an example of vortex-induced oscillation of bridge deck and its lesson are discussed. Next, the wind-induced cable vibration and its aerodynamic countermeasures are reviewed. Then, the aerodynamic characteristics on two edge girders and their feasibility for application to long span cable-stayed bridges are considered. Furthermore, the bridge decks for future long span bridges are proposed and their aerodynamic characteristics are also discussed.

Influence of geometric configuration on aerodynamics of streamlined bridge deck by unsteady RANS

  • Haque, Md. N.;Katsuchi, Hiroshi;Yamada, Hitoshi;Kim, Haeyoung
    • Wind and Structures
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    • v.28 no.5
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    • pp.331-345
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    • 2019
  • Long-span bridge decks are often shaped as streamlined to improve the aerodynamic performance of the deck. There are a number of important shaping parameters for a streamlined bridge deck. Their effects on aerodynamics should be well understood for shaping the bridge deck efficiently and for facilitating the bridge deck design procedure. This study examined the effect of various shaping parameters such as the bottom plate slope, width ratio and side ratio on aerodynamic responses of single box streamlined bridge decks by employing unsteady RANS simulation. Steady state responses and flow field were analyzed in detail for wide range of bottom plate slopes, width and side ratios. Then for a particular deck shape Reynolds number effect was investigated by varying its value from $1.65{\times}10^4$ to $25{\times}10^4$. The aerodynamic response showed very high sensitivity to the considered shaping parameters and exhibited high aerodynamic performance for a particular combination of shaping parameters.

A comparative study of numerical methods for fluid structure interaction analysis in long-span bridge design

  • Morgenthal, Guido;McRobie, Allan
    • Wind and Structures
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    • v.5 no.2_3_4
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    • pp.101-114
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    • 2002
  • Both a Finite Volume and a Discrete Vortex technique to solve the unsteady Navier-Stokes equations have been employed to study the air flow around long-span bridge decks. The implementation and calibration of both methods is described alongside a quasi-3D extension added to the DVM solver. Applications to the wind engineering of bridge decks include flow simulations at different angles of attack, calculation of aerodynamic derivatives and fluid-structure interaction analyses. These are being presented and their specific features described. If a numerical method shall be employed in a practical design environment, it is judged not only by its accuracy but also by factors like versatility, computational cost and ease of use. Conclusions are drawn from the analyses to address the question of whether computer simulations can be practical design tools for the wind engineering of bridge decks.

The effect of Reynolds numbers on the steady state aerodynamic force coefficients of the Stonecutters Bridge deck section

  • Hui, M.C.H.;Zhou, Z.Y.;Chen, A.R.;Xiang, H.F.
    • Wind and Structures
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    • v.11 no.3
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    • pp.179-192
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    • 2008
  • In a wind tunnel experiment employing a reduced scale model, Reynolds number (Re) can hardly be respected. Its effects on the aerodynamics of closed-box bridge decks have been the subject of research in recent years. Stonecutters Bridge in Hong Kong is a cable-stayed bridge having an unprecedented central span of 1018m. The issue of Re sensitivity was raised early in the design phase of the deck of Stonecutters Bridge. The objective of this study is to summarise the results of various wind tunnel experiments in order to demonstrate the effect of Re on the steady state aerodynamic force coefficients. The results may provide an insight on the choice of scale for section model experiments in bridge design projects. Computational Fluid Dynamics (CFD) analysis of forces on bridge deck section was also carried out to see how CFD results are compared with experimental results.

The aerodynamic characteristics of twin column, high rise bridge towers

  • Ricciardelli, Francesco;Vickery, Barry J.
    • Wind and Structures
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    • v.1 no.3
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    • pp.225-241
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    • 1998
  • The high-rise supporting towers of long-span suspension and cable-stayed bridges commonly comprise a pair of slender prisms of roughly square cross-section with a center-to-centre spacing of from perhaps 2 to 6 widths and connected by one or more cross-ties. The tower columns may have a constant spacing as common for suspension bridges or the spacing may reduce towards the top of the tower. The present paper is concerned with the aerodynamics of such towers and describes an experimental investigation of the overall aerodynamic forces acting on a pair of square cylinders in two-dimensional flow. Wind tunnel pressure measurements were carried out in smooth flow and with a longitudinal intensity of turbulence 0.10. Different angles of attack were considered between $0^{\circ}$ and $90^{\circ}$, and separations between the two columns from twice to 13 times the side width of the column. The mean values of the overall forces proved to be related to the bias introduced in the flow by the interaction between the two cylinders; the overall rms forces are related to the level of coherence between the shedding-induced forces on the two cylinders and to their phase. Plots showing the variation of the force coefficients and Strouhal number as a function of the separation, together with the force coefficients spectra and lift cross-correlation functions are presented in the paper.

The analysis of flow over the bridge using preconditioned Navier-Stokes code (예조건화 Navier-Stokes 코드를 이용한 교각 유동해석)

  • Yoo, Il-Yong;Lee, Seung-Soo;Park, Si-Hyong
    • 한국전산유체공학회:학술대회논문집
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    • pp.13-16
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    • 2008
  • After the collapse of the Tacoma bay bridge at Tacoma Washington, the accurate prediction of aerodynamics became crucial to the sound design of bridges. CFD(Computational Fluid Dynamics) becomes important tool for the prediction on wind effects on the bridge due to the recent development of CFD. The usage of CFD is further prompted by the advantages in using CFD, such as low-cost and fast feed-back of design. In this paper, an unsteady compressible Reynolds averaged Navier-Stokes code is used for the computation of the flow over bridges. Coakley's ��q-${\omega}$ �� two-equation turbulence model is used for the turbulent eddy viscosity. For accurate and stable computations, the local preconditioning method is adapted to the code. Aerodynamic characteristics of a couple bridges are presented to show the validity and the accuracy of the method.

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A study of wind effect on damping and frequency of a long span cable-stayed bridge from rational function approximation of self-excited forces

  • Mishra, Shambhu Sharan;Kumar, Krishen;Krishna, Prem
    • Wind and Structures
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    • v.10 no.3
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    • pp.215-232
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    • 2007
  • This paper presents an aeroelastic analysis procedure to highlight the influence of wind velocity on the structural damping and frequency of a long span cable-stayed bridge. Frequency dependent self-excited forces in terms of flutter derivatives are expressed as continuous functions using rational function approximation technique. The aeroelastically modified structural equation of motion is expressed in terms of frequency independent modal state-space parameters. The modal logarithmic dampings and frequencies corresponding to a particular wind speed are then determined from the eigen solution of the state matrix.