Enhancement of low-frequency vibration suppression in reconfigurable multiphase negative Poisson's ratio metamaterials

In this study, we design reconfigurable multi-phased negative Poisson's ratio metamaterial (NPM) for low-frequency vibration reduction. The designed NPMs consist of a concave hexagonal skeleton and horizontal diamond-shaped counterweights, which incorporate a base material and replaceable metal cores. By replacing these metal cores, the bandgap can be reconfigured and adjusted as needed. Finite element simulations and excitation experiments are employed to investigate the vibration suppression effects of these NPMs. The results show that the three-phase NPM has more advantages in low-frequency vibration reduction, compared with the single-phase and two-phase NPMs. When the metal core of the three-phase NPM is made of a higher-density material (lead), the lower edge of the bandgap is as low as 471.4 Hz, and the bandgap coverage below 1000 Hz reaches 36.1 %. These findings provide new ideas for low-frequency vibration reduction in engineering practice.