Influence of cell parameters in local resonator-based metamaterials

Band gap characteristic of flexural metamaterial beams has been an active area of research for its potential application in providing low-frequency band gaps. The present work brings out investigations on flexural metamaterial beams, highlighting the influence of their design parameters. The metamaterial beams were fabricated by introducing periodic cavities in a thin uniform beam, and filling the cavities by a Viscoelastic Membrane (VEM), and a Resonant Mass (RM). Twelve different metamaterial beams were fabricated for experimental and numerical investigations, by varying the geometrical shape of the cavity or the type of VEM or the mass of RM. Vibration characteristics and band gaps of these metamaterial beams were studied through vibration trials on a vibration shaker. Their vibration characteristics were compared with that of a uniform beam, without any cavity. Two prominent low-frequency band gaps were discernible for the metamaterial beams, which are referred to as 'local resonance band gaps (LRBGs)'. Dependence of these LRBGs on various design parameters of the metamaterial beam has been presented. Further, the band gap characteristic of a metamaterial beam has been compared to that of a beam with multiple-Tuned Mass Dampers to get further insight into the band gaps of a metamaterial structure.