Multimodal Vibration Control of the Cable Network in Suspension Bridges Through a Tuned Inerter Damper-Based Hybrid Measure

As the essential stress component of suspension bridges, suspender cables are characterized by light weight, high flexibility, and low inherent damping, being therefore highly susceptible to wind excitations. This research proposes a tuned inerter damper (TID)-based hybrid measure, i.e. comprising a TID and a spacer, to mitigate the multimodal vibration of the suspender cable network. The governing equations of a cable network with a TID and a spacer are derived through the finite difference method (FDM), and are verified by existing studies. The thorough parametric analyses in terms of stiffness and position of spacer, as well as stiffness and inertance of TID, are conducted according to an optimal performance index of multimodal damping ratio, and the damping performance of TID is compared to that of a viscous damper (VD). The analysis results show that the TID can obtain the superior multimodal damping ratio as well as the modal damping ratio of multiple cable modes than the VD over a broad range of TID parameters. Finally, the effectiveness of the TID-based hybrid control measure in suppressing the vortex-induced vibration (VIV) of the suspender cable network is evaluated under both uniform and shear wind flows. The TID-based hybrid measure is more effective in reducing displacement response than the VD-based measure, representing its reliability and efficiency.