Series gravity-based track nonlinear energy Sinks: Design and experiment

Abstract

How to improve the robustness of nonlinear energy sinks (NES) to excitation strength is always a challenging issue in the design of NES. This paper combines the gravity-based track NES (GT-NES) with the two-degree-of-freedom (2DOF) series design strategy and proposes a 2DOF series gravity-based track NES (SGT-NES) to increase the robustness of excitation and achieve a large parameter selection range. For the single-degree-of-freedom system, the vibration reduction dynamic model of SGT-NES, series NES, and GT-NES is established. Through dynamic analysis, the influence of parameters on the vibration reduction of SGT-NES is studied and verified by numerical simulation. In addition, the vibration reduction performance of SGT-NES, series NES, and GT-NES is compared. The results show that SGT-NES can achieve effective vibration reduction in a wider parameter range. Moreover, SGT-NES can maintain a large parameter range without frequency islands. Therefore, SGT-NES exhibits a stronger adaptability to excitation strength. A two-degree-of-freedom SGT-NES prototype is designed. The vibration reduction of SGT-NES and its parameter influence trend are verified by experiments. Therefore, this research proposes an effective device with a wide range of parameter adaptability for engineering vibration control.