Feasibility study of wind tunnel aeroelastic tests on bridges with floating towers

Author(s):  
Tommaso Argentini ◽  
Claudio Montagna ◽  
Daniele Rocchi

<p>Floating towers are an innovative design solution for long-span bridges crossing deep waters, where grounded towers are not applicable. This kind of structural solution brings about challenging issues related to the design of such structures exposed to the combined action of aerodynamic forces and hydrodynamic forces. One of the major issues is the experimental validation of numerical models to simulate the structural dynamics, based on hybrid codes joining aero-elastic and hydro-elastic interactions.</p><p>This paper presents a feasibility study of wind-tunnel aeroelastic tests, where the submerged part of the bridge is simulated by Hardware-In-the-Loop (HIL) technology: actuators simulates the motion of the floater due to the combined action of the hydrodynamic loads on the floater (numerically simulated in real time) and of the aerodynamic and inertial loads transmitted by the tower (measured by a 6-components dynamometer). A similar HIL testing device has been developed at POLIMI in the field of floating offshore wind turbines, and it is likely to be applied to long-span bridges, as a tool for the experimental validation of complex numerical hybrid approaches.</p><p>The opportunities offered by this technology will be discussed in the paper, working out a numerical example where the full-scale response of a FEM of the full-bridge is simulated and then it is scaled in order to assess the feasibility of aeroelastic tests in wind tunnel, with a focus on the characteristics of the actuation system for the tower base: necessary of degrees of freedom, amplitude and bandwidth of motion and force.</p>

2021 ◽  
Vol 11 (4) ◽  
pp. 1642
Author(s):  
Yuxiang Zhang ◽  
Philip Cardiff ◽  
Jennifer Keenahan

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.


Author(s):  
Giorgio Diana ◽  
Stoyan Stoyanoff ◽  
Andrew Allsop ◽  
Luca Amerio ◽  
Tommaso Argentini ◽  
...  

<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>


2018 ◽  
Vol 245 ◽  
pp. 02001 ◽  
Author(s):  
Evgenii Khrapunov ◽  
Sergei Solovev

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.


2020 ◽  
pp. 107754632094615
Author(s):  
Yanguo Sun ◽  
Yongfu Lei ◽  
Ming Li ◽  
Haili Liao ◽  
Mingshui Li

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.


2014 ◽  
Vol 633-634 ◽  
pp. 1263-1266
Author(s):  
Huang Yu

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.


1992 ◽  
Vol 42 (1-3) ◽  
pp. 885-896 ◽  
Author(s):  
T. Miyata ◽  
H. Yamata ◽  
K. Yokoyama ◽  
T. Kanazaki ◽  
T. Iijima

2018 ◽  
Vol 195 ◽  
pp. 02032
Author(s):  
Suangga Made ◽  
Irpanni Herry

Indonesia is the world’s largest archipelago with many major rivers in the big islands of Sumatera, Kalimantan, and Java. As part of its road network, major bridges are constructed to cross these rivers. Considering the span of the bridges and its aesthetic point of view, the application of Long Span Steel Truss Bridges in Indonesia is very popular among others. Its span varies from 70 to 270 meters in length. For long span bridges, aerodynamics is an important aspect for the design and construction of the bridges. In order to ensure the stability of the bridges against the aerodynamic effect of the wind, wind tunnel study and test has been conducted for most of the bridges. This paper presents the parameter and characteristic of several Long Span Steel Truss Bridges in Indonesia, i.e. Tayan Kapuas Bridge, Musi VI Bridge, New Kutai Kartanegara Bridges and Teluk Mesjid Bridge. The bridges will be assessed against BD 49/01. Parameters and assessment results are then compared with wind tunnel results.


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