Paper detail

Multi-resonant scatterers in Sonic Crystals: Locally Multi-resonant Acoustic Metamaterial

An acoustic metamaterial made of a two-dimensional (2D) periodic array of multi-resonant acoustic scatterers is analysed in this paper. The building blocks consist of a combination of elastic beams of Low-Density Polyethylene Foam (LDPF) with cavities of known volume. Sound inside the structure can excite elastic resonances of the material as well as acoustic resonances in the cavities producing several attenuation peaks in the low-frequency range. Due to this behaviour at the subwavelength regime we can define this periodic array as a Locally Multi-Resonant Acoustic Metamaterial (LMRAM) presenting strong dispersive characteristics of the effective properties with subwavelength multi-resonant structural units. The results shown in this paper could be use to design effective Sonic Crystal Acoustic Barriers with wide tunable attenuation bands in the low-frequency range.