Bandgap and wave attenuation mechanisms of innovative reentrant and anti-chiral hybrid auxetic metastructure

Rational design of artificial micro-structured metamaterials with advanced mechanical and physical properties that are not accessible in nature is challenging and important. Making use of the node rotation and ligament bending deformation features of chiral materials, innovative reentrant and anti-chiral hybrid metastructures are proposed for vibration attenuation, where elastic rubber coated mass inclusions are distributed within the chiral circular ring nodes of unit cells. The bandgaps and wave attenuation mechanisms of the proposed reentrant and anti-chiral hybrid metastructures are explored, and finite element simulations are performed for analyzing the relation between wave attenuation properties and structural parameters. Then, coupled deformation mechanism of reentrant and anti-chiral hybrid metastructures are analyzed, it is found that the geometrical topology and node elastic mass inclusion distribution schemes have remarkable effects on the bandgaps of the metastructures. Meanwhile, the wave mitigations of the reentrant and anti-chiral hybrid metastructures are explored through tuning the structural parameters and mass inclusions distributions. Finally, the wave attenuation performances of sandwich panels with reentrant and anti-chiral hybrid cores are studied, thus demonstrating the promising engineering application potentials for vibration isolation.