A fish-skeleton-like metastructure isolator for low-frequency vibration isolation

Vibration isolation for vibration-isolated objects in low-frequency vibration environment has been widely concerned by researchers. In this paper, we designed a local resonant (LR) fish-skeleton-like metastructure isolator with cantilever beam oscillators for low-frequency vibration isolation. Based on the theories of wave dynamics and structural dynamics, we analytically obtained the bandgap character-istics and transmissibility of the metastructure by using the equivalent mass and stiffness method, and carried out simulations through the finite element method (FEM). This metastructure isolator was fabri-cated by a 3D printing equipment and the vibration isolation test was carried out. Vibration transmissi-bility characteristics is obtained through the analytical method, FEM and experiment show that the local resonance near the natural frequency of the oscillators can effectively suppress the vibration transmis-sion. The specific performance shows that the vibration transmissibility is as low as 21 % at the center frequency of the bandgap, while the mass of the isolator is only increased by about 2.3 % compared with the ordinary structure which has no oscillators. With the increasing of the mass of vibration-isolated objects (650 g), the transmissibility can be as low as 4 %. In addition, the contribution of different frame bodies and different oscillators of the isolator on the isolation effect and a way of widening the isolation frequency ranges are clarified. The proposed fish-skeleton-like metastructure in the present work pro -vides a new design approach for vibration isolation in engineering applications.(c) 2023 Published by Elsevier Ltd.