A bio-inspired metamaterial for attenuating vibration with a compression-torsion coupling effect

Mechanical metamaterials have received a lot of interest because of their exceptional physical characteristics and numerous potential applications. A bio-inspired chiral metamaterial with a compression-torsion coupling effect to generate a low-frequency bandgap is presented, drawing inspiration from the legs of birds. We quantitatively study the transmissibility, vibration eigenmodes, and band structures of chiral metamaterials. With the use of additive manufacturing, vibration tests are used to confirm the metamaterial’s dynamic response and bandgap. The metamaterial produces broad full bandgaps and strong transmissibility attenuation in the frequency range of 86–243 Hz and 102–924 Hz, according to experimental and numerical data. We discover that the main reason for the creation of bandgaps is the increased torsional inertia that the compression-torsion coupling effect provides. Furthermore, the position and width of complete bandgaps (CBGs) are profoundly affected by the geometric variables; for example, the width of the first bandgap grows as the radius of the circle made up of the four center nodes of the linkage, r, increases. The proposed bionic compression-torsion coupling metamaterials exhibit the unique benefits of a wide bandgap and low frequency, offering a wide range of potential applications in vibration attenuation and control.