Study on adaptive-passive eddy current pendulum tuned mass damper for wind-induced vibration control

Tuned mass dampers (TMDs) are used to control wind-excited responses of high-rise building as traditional vibration control devices. A TMD will have an excellent control effect when it is well tuned. However, a traditional passive TMD is sensitive to the frequency deviation; the mistuning in frequency and damping ratio both will decrease its control effect. In the previous research, an adaptive-passive variable pendulum TMD (APVP-TMD) is proposed, which can identify the TMD optimal frequency and retune itself through varying its pendulum length. However, it is found that the frequency variation will change the TMD damping ratio, and an unreasonable damping ratio will lead to a decrement in the robustness of a TMD. In this study, an adaptive-passive eddy current pendulum TMD (APEC-PTMD) is presented, which can retune the frequency through varying the pendulum length, and retune the damping ratio through adjusting the air gap between permanent magnets and conductive plates. An adjustable eddy current pendulum TMD (PTMD) is tested, and then, a single-degree-of-freedom (SDOF) primary model with an APEC-PTMD is built, and functions of frequency and damping ratio retuning are verified. The 76-story wind-sensitive benchmark model is proposed in the case study. The original model without uncertainty and +/- 15% stiffness uncertainty models are considered, and response control effects of different controllers are compared. Results show that because the APEC-PTMD can both retune its frequency and damping ratio; it is more robust and effective than a passive TMD. It is also found that the APEC-PTMD has a similar control effect with the active TMD, with little power consumption and better stability.