Feasible control solutions of the ASCE benchmark cable-stayed bridge

A benchmark model of a cable-stayed bridge has attracted in the last years the attention of the control community. In this paper robust feasible solutions are investigated. As a first step passive devices have been applied to the bridge numerical model between the deck and the piers. Further, an open-loop semi-active improvement of the passive control system is implemented, as suggested by the preliminary results. Finally, an innovative decentralized solution for a semi-active scheme in closed-loop configuration is introduced in the bridge model; the results are here compared, in terms of structural responses, with an active setting, defining an optimal target. The control algorithm adopted for the semi-active devices in the closed-loop setting is an on/off skyhook one with two force levels. The devices adopted in the numerical simulations have dissipative properties and, when managed in a semi-active arrangement, act as a 3D smart control system. The device force displacement relationship fits the results of laboratory tests during the characterization process of an electro-inductive device. The excitation considered in the benchmark problem is essentially the seismic one. A digression to the wind excitation is introduced in the numerical model so as to analyze the control system reaction. The aim of this study is to suggest control solutions for cable-stayed bridges with the common sense to research the best performance, though maintaining robustness, simplicity and feasibility.