Research on a Double-Arrow Metamaterial Quasi-Zero-Stiffness Isolator

A vibration isolator is an elastic element connecting a foundation and equipment, widely used in daily life and industrial production. Generally, the better the isolation effect of an isolator, the lower its natural frequency, with a corresponding reduction in stiffness. However, reduced stiffness leads to increased deformation of the isolator, meaning greater static displacement under identical conditions. Quasi-zero stiffness (QZS) isolators feature high static stiffness and low dynamic stiffness, enabling reduced system stiffness while minimizing isolator deformation. This study designs a QZS isolation system based on a double-arrow negative Poisson’s ratio metamaterial structure and derives its vibration control equation. Static and dynamic characteristics of the QZS system are analyzed, along with the influence of parameters on isolation performance, yielding optimal parameters for achieving quasi-zero stiffness. A prototype of the double-arrow QZS isolation system was fabricated, and its responses under different excitation amplitudes and frequencies were measured. Comparison with theoretical results verifies the correctness of the theoretical analysis. The findings demonstrate that with appropriate configuration, the QZS isolator exhibits significantly better isolation bandwidth and performance than the corresponding linear isolation system, with a marked reduction in natural frequency, enabling effective low-frequency vibration isolation.