Conference Paper Experimental flutter suppression of a long-span suspension bridge section

Gouder, Kevin  ,  Zhao, Xiaowei  ,  Limebeer, David  ,  Graham, J. Michael R.

The suppression or delay of flutter in long-span suspension bridges is investigated experimentally. Since the torsional stiffness of a bridge deck decreases with increasing length, an active flap flutter suppression system could potentially enable the construction of longer spans without costly increases in deck width and depth. An active flap flutter suppression system could be deployed as a temporary measure during construction when the deck, not yet tied down at one or both ends, is particularly vulnerable to flutter instability. In the current experiment, a rigid sectional model of a long-span suspension bridge is mounted on a suspension system in a wind tunnel. Moving flaps attached to the bridge section's leading and trailing edges are controlled in real-time in response to the bridge section's heave and pitch motions. Other modes of bridge section motion, such as sway, were suppressed through the use of drag wires. Experimental assessment of the deck's aerodynamic derivatives and their similarity to those of a flat plate justified the aerodynamic force modeling using a theoretical model based on Theodorsen's theory; the flap control system is designed through an H∞ optimisation. The control system design was constrained to low-order passive controllers that could be effectively replaced by reliable, passive (no external energy input) mechanical networks that drive the flaps through the bridge deck motion. The flutter-suppression effectiveness of various controllers with one or both actuated flaps, and different feedback quantities including one, or a combination of the bridge section's pitch angle and heave positions or velocities, was tested. Flutter velocity increases in excess of 20% were attained with very good robustness margins.
Meeting Information: First International Symposium on Flutter and its Application (May 15-17, 2016. Mielparque-tokyo), Minato-ku, Tokyo, Japan
Physical characteristics: Original contains color illustrations
形態: カラー図版あり

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