Multi-mode vortex-induced vibration control of long-span bridges by using distributed tuned mass damper inerters (DTMDIs)

Tuned mass damper inerter (TMDI) has been proved to be a feasible device for vibration control of long-span bridges due to its excellent space performance. However, existing design method for TMDI is conducted mode-by-mode. When applied to multi-mode control of the bridge through multiple TMDIs, it cannot consider the synergistic effect among the TMDIs and thus leading to a suboptimum design result. This paper presents an efficient method for multi-mode vortex-induced vibration (VIV) control of long-span bridges by using spatially distributed TMDIs (DTMDIs). The governing equations of the bridge-DTMDIs system are established in modal coordinate. A global optimization method considering the synergistic effect among the DTMDIs is proposed and compared with conventional mode-by-mode approach through a numerical case study. The robustness of the control schemes against variations in structural and aerodynamic parameters is investigated. The influence of inerter span length on the control efficiency is also discussed. The results show that the proposed global design method can achieve a better control efficiency with even less TMDIs as compared with conventional mode-by-mode approach. The proposed method can also be extended to VIV control of some other line-like structures.