An acoustic metamaterial made of a two-dimensional (2D) periodic array ofmulti-resonant acoustic scatterers is analysed in this paper. The buildingblocks consist of a combination of elastic beams of Low-Density PolyethyleneFoam (LDPF) with cavities of known volume. Sound inside the structure canexcite elastic resonances of the material as well as acoustic resonances in thecavities producing several attenuation peaks in the low-frequency range. Due tothis behaviour at the subwavelength regime we can define this periodic array asa Locally Multi-Resonant Acoustic Metamaterial (LMRAM) presenting strongdispersive characteristics of the effective properties with subwavelengthmulti-resonant structural units. The results shown in this paper could be useto design effective Sonic Crystal Acoustic Barriers with wide tunableattenuation bands in the low-frequency range.
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