Experimental study on vibration mitigation of bridge stay cables using cross-ties and hybrid system.

摘要

Controlling excessive vibrations of stay cables on cable-stayed bridges is important to minimize the fatigue failure and damage at the cable anchorages. Using cross-ties to connect a vulnerable cable with its neighbors to form a cable network and installing external damper to a cable have been widely used in field. More recently, the idea of adding damper to an existing network to form a hybrid system was also proposed. Though the stiffening effect of the cross-tie solution are widely studied by numerous researchers, the damping property of a network has rarely been investigated. Also, the available studies on the hybrid system are very limited. In the present work, experimental study was carried out to investigate the modal behavior of a cable network in terms of its first modal frequency and damping. The efficiency of the damper-only solution and hybrid system solution with different configurations were also examined and the results were compared. Then, an independent finite element simulation was conducted. The two sets of results agree well. They both indicate that the cross-tie solution improves the stiffness of the target cable, the damper-only solution enhances its energy dissipation, and the hybrid system increases both the stiffness and the damping of the target cable.