Flutter performance and aerodynamic mechanism of plate with central stabilizer at large angles of attack

Abstract

To analyze the effects of a central stabilizer on the flutter performance at large angles of attack, this study takes the ideal plate as a section of a bridge deck. The aerodynamic characteristics of stationary cross sections are examined using computational fluid dynamics simulations, and the flutter derivatives are extracted by forced vibration. The critical flutter speed of a target bridge is then calculated, and the aerodynamic mechanism of the central stabilizer is discussed from the work done by aerodynamic forces’ perspective. The results show that use of a central stabilizer with lower heights favors flutter stability at smaller angles of attack by improving the participation level of heaving motion, but the stability of the systematic heaving motion will decrease if the stabilizer is too high, leading to galloping. At larger angles of attack, where the movement of a big vortex causes the occurrence of torsional flutter, the stabilizer can hinder the movement of the vortex if they are on the same side, and the critical flutter speed increases with the increase in stabilizer height.

Effects of guardrails on wind environment for vehicles and aerodynamic stability for bridges with box girders

“…As previous studies have described (Guo et al, 2020; Tang et al, 2018), the movement of vortex formed at the windward side toward the leeward side is the main cause of flutter. When the box girder moves clockwise, the vortex exists on the windward side of the box girder, and when the box girder moves counterclockwise, the vortex just moves to the leeward side of the box girder, and the vortex will promote the rotation of the box girder.…”

Optimization for vertical stabilizers on flutter stability of streamlined box girders with mountainous environment

“…Here, α = 0° and −8° which represent the effects of small and large angles of attack, respectively, are taken as the examples. At large angles of attack, the flutter stability of bridge is improved with the increase in stabilizer’s height (Tang et al, 2018), so a larger height of 0.08 B is set first. At small angles of attack, a higher stabilizer may have adverse effects on the flutter stability (Tang et al, 2018), so a lower height of 0.04 B is set first.…”

“…At large angles of attack, the flutter stability of bridge is improved with the increase in stabilizer's height (Tang et al, 2018), so a larger height of 0.08B is set first. At small angles of attack, a higher stabilizer may have adverse effects on the flutter stability (Tang et al, 2018), so a lower height of 0.04B is set first. Different heights of the stabilizer will also be considered later.…”

“…The existence of central slot makes the flow field around the girders complicated at large angles of attack, which may even reduce the critical flutter wind speed of bridge. For what concerns the vertical stabilizer, Tang et al (2018) studied the flutter stability of an ideal plate. The stabilizer could improve the critical flutter wind speed of bridge by blocking the movement of vortex at large angles of attack, and higher stabilizers may achieve better results.…”

Vortex-induced vibration of a truss girder with high vertical stabilizers

“…These vertical stabilizers installed along the bridge span make the truss girder present the characteristics of a bluff body more, calling for further investigations on the vortex-induced vibration. Tang et al (2018) simplified the actual girder as an ideal thin flat plate to analyze the effect of the vertical stabilizer on structural aerodynamic stability and found that higher vertical stabilizers increase the possibility of vortex-induced vibration or galloping. Therefore, it is very necessary to study the performance of vortex-induced vibration of the truss girder with high vertical stabilizers.…”