斜杆拉簧负刚度机制的恒值准零刚度超低频隔振设计

Constant Quasi-zero Stiffness Ultra-low Frequency Vibration Isolator Design Based on Negative Stiffness Mechanism Composed of Oblique Bars and Tension Spring

准零刚度隔振器相比线性隔振器,具有宽频、低传递率的优良隔振性能,是一种应用前景较好的被动式隔振器。但单个静态平衡点的准零刚度隔振器在变承载质量隔振、大幅激励隔振方面存在问题,因此基于斜杆拉簧恒值负刚度机制构造了恒值准零刚度隔振器,推导出了恒值准零刚度、非恒值准零刚度、零刚度的参数条件,分析了参数影响下的准零刚度特性和规律。设计并制造了实验模型,根据恒值准零刚度参数条件装配实验模型,通过万能试验机获得了实验模型的力位移曲线,与理论预测值一致性较好,验证了静态分析理论。随后采用Polytec激光测振仪和振动台对恒值准零刚度实验模型开展了动态实验,获得的实验传递率与理论预测值一致性较好,具有起始隔振频率接近1 Hz的较宽频带和较低传递率幅值。

Compared with linear vibration isolator,quasi-zero stiffness vibration isolator has excellent vibration isolation performance with wide frequency and low transmissibility,and it is a kind of passive vibration isolator with better application prospect.However,the quasi-zero stiffness isolator with a single static equilibrium point has problems in the variable bearing mass isolation and large excitation isolation.For solving the problems,a constant-value quasi-zero stiffness isolator is constructed by using the constant-value negative stiffness mechanism of oblique bars and tension springs.The parameter conditions of constant-value quasi-zero stiffness,non-constant-value quasi-zero stiffness and zero stiffness are derived,as well as the characteristics of quasi-zero stiffness and the law under the influence of the parameters are analyzed.The experimental model is then designed,manufactured and assembled according to the constant-value quasi-zero stiffness parameter conditions.The universal testing machine is used to obtain the force-displacement curves which corresponded well with theoretical predictions,providing verification for the static analysis theory.Subsequently,the Polytec laser vibrometer and the shaking table are used to collect dynamic experiments results on the experimental model with constant-value quasi-zero stiffness.The experimental transmissibility is consistent with theoretical predictions well.The isolator has the wide bandwidth with the starting isolation frequency of close to 1 Hz and low transmissibility amplitude.