Flexural wave propagation in metamaterial beams containing membrane-mass structures

This study addresses the flexural behavior of the metamaterial beam containing membrane-mass structures that can be used as local resonators. The finite elements method is employed to predict dispersion relations and the bandgap structure of the proposed metamaterial beam. By altering mass location, membrane tension, and mass magnitude, the characteristics of the bandgap can be easily tuned. Multiple resonant-type bandgaps can be achieved by varying the mass distribution across cells of the metamaterial beam. To precisely capture the resonance frequency of the membrane-mass structure, an analytical model is introduced. The effect of membrane dimensions on bandgap characteristics is also examined.