Effect of structural control on wind fatigue mitigation in suspension bridges

Vibrations induced by wind actions are regarded as one of the sources of fatigue failures for the structural steel members of long-span bridges. This work deals with structural control solutions, namely passive and decentralised semi-Active ones, which can give a significant contribution in mitigating such effects. The selected control strategies, which were optimised in a previous research work on a validated finite element model of an existent suspension bridge, are herein evaluated for controlling wind induced fatigue problems in the steel deck. Standard deviation of the bending moment along the bridge deck, in association with local stresses in structural details, is recognised as a parameter related to fatigue damage accumulation. The proposed control strategies demonstrate able to significantly reduce such damage. Furthermore, passive and semi-Active solutions have comparable effectiveness in terms of mitigating damage due to fatigue.