An elastic metamaterial beam for broadband vibration suppression

One of the significant engineering applications of the elastic metamaterial is for the low-frequency vibration absorption because of the existence of low-frequency bandgaps. However, the forbidden gap from existing elastic metamaterials is of narrow bandwidth which limits their practical engineering application. In this paper, a chiral-lattice-based elastic metamaterial beam with multiple resonators is suggested for the broadband vibration suppression by overlapping their resulting bandgaps. First, a theoretical modeling of the metamaterial beam with periodically multiple resonators is performed for bending wave propagation. The wave interaction between the multiple resonators is found to generate new passbands, which is a barrier to form a complete bandgap. To address this issue, a section distribution of the multiple resonators is suggested to diminish the interaction. Finally, the chiral-lattice-based metamaterial beam is fabricated and experimental testing of the structure is conducted to validate the proposed design. This work can serve as a theoretical and experimental foundation of the broadband vibration suppression by using the metamaterial structure in practical engineering applications.