Vortex-induced vibration mitigation of the circular cylinder using a nonlinear energy sink with an inerter

This paper presents a novel inerter-based nonlinear energy sink (NESI) to mitigate the vortex-induced vibration of the circular cylinder. The primary objective is to reduce the secondary mass of the traditional NES by introducing an inerter while maintaining its original vibration suppression performance. Firstly, numerical simulations reveal that the introduction of an inerter can enable the natural frequency of the coupled NES-cylinder system to become closer to the vortex shedding frequency in the wake, thereby extending the resonance duration between the circular cylinder and NES. Secondly, this work investigates the impact of the inerter on the dynamic characteristics of NES using wavelet decomposition, reconstruction and Hilbert-Huang transform methods. It is observed that both increasing the additional mass of the NES and incorporating an inerter enhance the transition path between stable branches in the coupled system, which prolongs the resonance capture time between the circular cylinder and NES/NESI. Finally, the analysis demonstrates that the introduction of the inerter not only significantly reduces the additional mass o required for the NES while preserving its control effectiveness but also extends the fatigue life of the controlled structure. The novelty of this study lies in the first application of the NES with the inerter for VIV suppression in circular cylinders and in uncovering the impact of the inerter on the dynamic behavior of the coupled NES-cylinder system. This research enriches the existing studies on NES involving an inerter and broadens the applicability of NES across diverse engineering fields.