一种几何非线性低刚度高阻尼隔振器动态特性研究

为了实现隔振器低动态刚度和高阻尼的设计目标，利用两层变杆长X型机构，提出一种新型隔振器.首先，采用谐波平衡法获得所建隔振系统动力学模型的稳态解析解，并分别给出隔振系统的幅频响应、相频响应、等效刚度、等效阻尼和力传递率.然后，根据力传递率，将新型隔振器与常规线性隔振器和准零刚度隔振器进行对比分析.同时，采用有限元方法对获得的解析解进行了有效性验证.最后，分析并给出系统参数对新型隔振器隔振性能的影响规律.结果表明：与常规线性隔振器相比，新型隔振器具备更小的动态刚度和更高的阻尼输出；与准零刚度隔振器相比，本新型隔振器除了能保证低刚度和高阻尼输出之外，还具有较好的稳定性与静承载能力；隔振系统设计参数对隔振性能均有较大影响，可通过灵活调整隔振系统各设计参数满足不同的隔振需求.

Study on Dynamic Characteristics of a Type of Vibration Isolator with Geometrically Nonlinear Low Stiffness and High Damping

A new type of vibration isolator is proposed by using a two-layer variable-bar length X-type mechanism in order to achieve the design objectives of the isolator with low dynamic stiffness and high damping. Firstly, the harmonic balance method is used to obtain the stationary analytical solution of the established mechanical model for the vibration isolation system, and the amplitude-frequency response, phase-frequency response, equivalent stiffness, equivalent damping and force transfer rate of the vibration isolation system are given respectively. Then, according to the force transmissibility, the vibration isolation performance is compared with conventional linear vibration isolator and quasi-zero stiffness vibration isolator. At the same time, the finite element analysis is carried out to verify the validity of the analytical solution. Finally, the influence law of the system parameters on the vibration isolation performance of the new type vibration isolator is analyzed and given. The results show that when compared with the conventional linear isolators, the new isolators have smaller dynamic stiffness and higher damping output, and when compared with the quasi-zero stiffness isolators, the new isolator not only can guarantee low stiffness and high damping output, but also has better stability and static bearing capacity. The design parameters of the vibration isolation system have a greater impact on the vibration isolation performance. Various design parameters of the vibration isolation system can be flexibly adjusted to meet different vibration isolation requirements.