Composite 3D-printed meta-structures for low frequency and broadband vibration absorption

TL;DR

This paper introduces composite 3D-printed meta-structures that achieve wide, low-frequency vibration and sound absorption band gaps with reduced mass, combining local resonances and lattice modes for enhanced control.

Contribution

The study presents a novel class of elastic meta-structures that combine local resonances with lattice modes to create broad, low-frequency band gaps while reducing overall mass, demonstrated through experiments and simulations.

Findings

Successfully created low-frequency band gaps using 3D-printed meta-structures.

Demonstrated control and broadening of band gaps via lattice geometry modifications.

Validated design principles with experimental and finite element simulation results.

Abstract

Architected materials that control elastic wave propagation are essential in vibration mitigation and sound attenuation. Phononic crystals and acoustic metamaterials use band gap engineering to forbid certain frequencies from propagating through a material. However, existing solutions are limited in the low frequency regimes and in their bandwidth of operation because they require impractical sizes and masses. Here, we present a class of materials (labeled elastic meta-structures) that supports the formation of wide and low frequency band gaps, while simultaneously reducing their global mass. To achieve these properties, the meta-structures combine local resonances with structural modes of a periodic architected lattice. While the band gaps in these meta-structures are induced by Bragg scattering mechanisms, their key feature is that the band gap size and frequency range can be controlled and broadened through local resonances, which is linked to changes in the lattice geometry. We demonstrate these principles experimentally, using novel additive manufacturing methods, and inform our designs using finite element simulations. This design strategy has a broad range of applications, including control of structural vibrations, noise and shock mitigation.