New designed quasi-zero-stiffness metamaterial for aerospace low-frequency vibration isolation

Abstract In view of the core requirements for low-frequency vibration isolation in the aerospace field, as well as the problems of complex design of traditional quasi-zero-stiffness (QZS) structures and insufficient bearing capacity of soft materials, this paper proposes a parallel cosine-beam QZS metamaterial. The structure realizes a stable QZS effect within a specific displacement range, taking into account the characteristics of high static load-bearing and low dynamic stiffness. The force-displacement model of a unit cell is established. The dispersion relation is derived by coupling the lumped-mass-spring model and Bloch’s theorem to analyze its local resonance bandgap characteristics. The quasi-static and vibration attenuation performances are verified through finite-element simulation and experiments. The results show that the pre-compression can reduce the starting frequency of the bandgap by up to 89 % . In the experiment, the overall bandgap occupation rate observed in the range of 1 − 300 Hz is approximately 91.7 % , demonstrating excellent low-frequency wide-band vibration isolation ability. This structure features a simple design and flexible parameter tuning. It is suitable for additive manufacturing and can be transitioned to metal materials. It is applicable to scenarios such as micro-vibration suppression of spacecraft and protection of ultra-precision equipment, providing an engineering path for low-frequency broadband vibration isolation.