An investigation of the active damping of suspension bridges

This paper explores the feasibility of active damping of suspension bridges with the addition of stay cables controlled by active tendons.An active tendon consists of a displacement actuator collocated with a force sensor monitoring the tension in the cable.The active tendons are controlled by decentralized integral force feedback (IFF).In the first part of the paper, the potential of the control strategy is evaluated on a numerical model of an existing footbridge; several configurations are investigated where the active cables connect the pylon to the deck or the deck to the catenary.The analysis confirms that it is possible to provide a set of targeted modes with a considerable amount of damping, reaching ξ = 15%.In the second part of the paper, the control strategy is demonstrated experimentally on a laboratory mock-up equipped with four control stay cables equipped with piezoelectric actuators.The experimental results confirm the excellent performance and robustness of the control system and the very good agreement with the predictions.