Summary With the development of megawatts wind turbines, excessive vibrations of the flexible and slender wind turbine tower under wind excitation have become increasingly prominent. To enhance implement ability of the passive control device for the tower, a new type of passive pre‐stressed tuned mass damper (PS‐TMD) is proposed in this study. A simplified mechanical calculation model of the tower with the PS‐TMD device is established, and the dynamic coefficient and vibration reduction mechanism are deduced through theoretical analysis. And then the design procedure including the optimal pre‐stress and damping coefficient for the proposed device is presented. The numerical simulation example shows that the tuning effect of PS‐TMD is better than the traditional tuned mass damper under the same conditions. The results from a shaking table test demonstrate that acceleration and dynamic displacement response are reduced about 20% and 30%, respectively.

Larger megawatt wind turbines are of significant height. The wind turbine tower (WTT) can suffer excessive vibration under external dynamic excitation, so an additional vibration control device is needed. Taking a novel prestressed tuned mass damper (PS-TMD) as the research object, its nonlinear vibration control performance induced by a flexible cable deformation effect was investigated. The dynamic coefficient amplitudes at two fixed points were derived based on the principle of virtual work, and results showed that the vibration amplitude considering flexible cable deformation is smaller than that of the linear PS-TMD system. For harmonic response, the numerical simulation of a 3.2 MW WTT indicated that vibration migration performance of the nonlinear PS-TMD is better than that of the linear PS-TMD. The Wilson-[Formula: see text] method was applied to analyze the vibration control effect under three fatigue and two ultimate wind loads. Results showed that the nonlinear PS-TMD can decrease the vibration amplitude more than the linear PS-TMD, and the vibration mitigation performance under the fatigue wind loads is slightly better than ultimate wind loads.

No abstract

No abstract

No abstract