基于非线性能量阱的双共振峰振动抑制的力学特性研究

非线性能量阱是一种可实现高效振动抑制的非线性吸振器。为了将其应用于宽频振动抑制问题,文章构造了一个由单自由度非线性能量阱和两自由度减振对象组成的系统,以研究非线性能量阱对双共振峰的振动抑制效果。结合系统特点,提出使用增量谐波平衡法分析系统共振峰附近的平衡点分布,并应用Floquet理论对平衡点的稳定性进行了判断,由此揭示了该系统局部分岔现象带来的复杂力学特性。为了验证解析结果,还进行了数值计算。研究结果表明非线性能量阱在正弦激励作用下具有良好的宽频减振效果,在航天器局部振动抑制方面具有良好的应用前景。

Dynamics of a nonlinear energy sink used for suppressing two-separated resonance peaks

The nonlinear energy sink is a nonlinear dynamic absorber for highly efficient vibration absorption.To suppress a broadband vibration of spacecrafts, a system consisting of a single degree-of-freedom(DOF) nonlinear energy sink and a two DOF main structure is constructed. This paper studies how the nonlinear energy sink(NES) can absorb the vibration energy efficiently in the modes of the main structure. To study the dynamics of the system, the periodic response near the resonance peaks is obtained by using the incremental harmonic balance method, and the stability of the periodic response is checked by using the Floquet''s theorem. The local bifurcation and the complex dynamics of the system are revealed, and the analytical results are verified numerically. The results suggest that the vibration suppression platform is effective for the broadband vibration induced by harmonic excitations, and the NES is favorable for the local vibration suppression of spacecrafts.