Three-dimensional lightweight chiral lattice metastructure for ultra-wide band vibration suppression

Abstract Elastic metastructures with local resonance bandgaps exhibit promising prospects for low-frequency vibration suppression. However, most existing local resonance metastructures suffer from narrow bandgaps and complex material compositions, which limit their engineering application potential. To address this, a novel three-dimensional (3D) chiral metastructure with ultra-wide bandgap characteristics was designed in this study. A finite element model of the unit cell was established to systematically analyze its band structure and explored the influence of geometric and material parameters on the bandgap. The simulation results indicated that the unit cell generates local resonance effects through interactions between the chiral framework, connecting rods, and mass blocks. It not only achieves a lightweight design with a relative density of 0.341, but also realizes an ultra-wide bandgap with a relative bandwidth of 1.51, where the thickness of the chiral framework is the key parameter affecting the bandgap of the unit cell. Furthermore, the specimens were fabricated using laser melting technology, and random vibration tests were used to verify the reliability of the simulation results. Effective ultra-wideband vibration control was successfully achieved in the frequency range of 420.1–3032.5 Hz. The proposed 3D chiral metastructure provides a new solution for wideband vibration suppression and is expected to promote the widespread application of metastructures in practical engineering.