Mitigation of Vortex-Induced Vibration in Bridges Using Semiactive Tuned Mass Dampers

With increases in the span length, the vortex-induced vibration (VIV) in bridges often occurs at modest wind velocities. The tuned mass damper (TMD) is very effective in mitigating the VIV, while robustness is a major concern for the TMD control with a small mass ratio. To improve the robustness, a magnetorheological TMD (MRTMD) instead of the TMD is used to mitigate the VIV with slowly time-varying frequency. A control strategy considering VIV characteristics is proposed for realizing the real-time tuning and mass stroke limitation simultaneously, including the control force design, control command determination, and frequency estimation. Numerical simulations of a long-span continuous bridge subjected to the VIV are presented to validate the feasibility of the control strategy and the superiority of the MRTMD control. Numerical results show that the MRTMD control is more robust against the resonant frequency change than the TMD control, and the maximum mass stroke is less than a preset stroke in both tuned and mistuned cases.