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Enhancement of the band-gap characteristics of hierarchical periodic elastic metamaterial beams

ABSTRACT Hierarchical periodic elastic metamaterial beams which can enhance the band-gap properties are designed by effectively combining the Bragg-scattering and locally resonant mechanisms. The frequency responses of the hierarchical periodic elastic metamaterial beams are calculated using the spectral element method (SEM). The correctness and feasibility of the present numerical method are verified by the vibration experiment. It is found that the design of the hierarchical periodicity can obtain more and broader band-gaps because the Bragg-scattering and locally resonant band-gaps can be generated simultaneously. The present results can provide a useful aid for the vibration reduction design of the elastic metamaterial structures in multi-frequency ranges.