一种悬臂梁组合几何非线性结构准零刚度隔振器研究

Research on a quasi-zero stiffness vibration isolator equipped with cantilever beam and geometrically nonlinear structure

为拓宽被动隔振器的隔振频率范围,实现低频甚至超低频隔振,研究了一种由负刚度机构与线性弹簧并联构成的准零刚度隔振器,其中负刚度机构由悬臂梁组合几何非线性结构构成。建立隔振器的静、动力学模型,得出了隔振器的恢复力-位移、刚度-位移曲线;分析隔振器在力激励下的幅频响应特性和稳定性,得出了阻尼及激励幅值对其隔振性能的影响规律。设计搭建机械式振动实验装置,对隔振器进行试验研究。理论分析及实验结果表明,在相同静态承载力下,所设计隔振器较对应线性隔振器,隔振频带更宽、隔振性能更优。本研究为准零刚度隔振器的设计提供了新的思路。

To broaden the vibration isolation frequency bandwidth of passive vibration isolator,realize low frequency and even ultra-low frequency vibration isolation,a quasi-zero stiffness vibration isolator(QZS-VI)composed of negative stiffness mechanism and linear spring was studied.The negative stiffness mechanism was composed of cantilever beam combined geometrically nonlinear structure.The static and dynamic models of the isolator were established,and the restoring force-displacement and stiffness-displacement curves of the isolator were obtained.The amplitude-frequency response characteristics and stability of the isolator under force excitation were analyzed,as well as the influence of damping and excitation amplitude on its vibration isolation performance.The mechanical vibration exciter was built to verify the isolation performance of proposed QZS-VI.Theoretical analysis and experimental results show that with the same bearing capacity,the proposed QZS-VI has broader vibration isolation frequency band than the corresponding linear isolator.This study provides a novel insight for the design of nonlinear QZS-VIs.