Development of an Inerter-Based Dynamic Vibration Absorber with Adjustable Inertance for Tower Structures: Theoretical Models, Experimental Validations, and Structural Behavior Insights

In the present study, an inerter-based dynamic vibration absorber (DVA) with a rhombus amplification mechanism inerter-based dynamic vibration absorber (R-IVA) was proposed toward effective vibration mitigation of tower structures with time-varying dynamic characteristics (e.g., frequency variation). Firstly, the theoretical model of structures equipped with the R-IVA was established, and the closed-form expression of the amplitude frequency response was obtained. Then, the effectiveness of the R-IVA for mitigating the vibration of tower structures was validated by a test program, and the validity of the theoretical model was confirmed by the test data. A parametric analysis based on the verified theoretical model was then performed to explore the influence of essential parameters of the R-IVAs. Subsequently, based on the H∞ optimization approach, governing equations quantifying the optimal parameters of the proposed R-IVA were derived. Finally, the applicability of the R-IVA and the adequacy of the optimization approach were demonstrated by numerical analyses on prototype wind turbine towers under seismic excitations. The experimental results conclusively demonstrated the efficacy of the R-IVA in mitigating the detuning phenomenon induced by time-varying dynamic characteristics of a tower structure. The effectiveness of the proposed R-IVA can be adjusted by modulating the initial assembly angle of the rhombus mechanism. The derived closed-form expression of the amplitude frequency response and the governing equations quantifying the optimal parameters of the R-IV can be used in practical applications with satisfactory accuracy.