A novel frog-like meta-structure with linkage mechanism for low-frequency vibration isolation

Abstract

Structures with linkage mechanism, which could be widely seen in engineering, usually need to bear a certain load and exhibit ideal vibration isolation performance. One of the key factors affecting the mechanical and vibration properties is the connection behavior of the linkage mechanism. To clarify its influence on the vibration characteristics, a novel frog-like meta-structure by introducing a linkage mechanism into the conventional locally resonant metamaterial with a mass-spring resonator is proposed in the present paper, in which the linkage connection is considered as three types of hinged, fixed and elastic, respectively. The equivalent dynamic model of the meta-structure is established theoretically to calculate the effective material properties, which is then validated numerically through band gap and vibration analysis. The results show that the hinged linkage offers equivalent mass and free vertical displacement, while the fixed linkage provides supporting stiffness, shifting the band gap towards higher frequencies. An appropriate elastic connection can enhance the ‘spring-vibrator’ effect, which in turn can significantly expand the low-frequency vibration suppression range of the structure. Experiments are also conducted corresponding to the different linkage mechanisms, and the dynamic model is verified. This study could provide a new idea for promoting the application of the locally resonant meta-structure with a linkage mechanism in the field of low-frequency vibration isolation.