PERFORMANCE OF ACOUSTIC METAMATERIAL BASED ON A DOU- BLE LAYER MICROPERFORATED PANEL

Resumo

In recent years, the development of models of acoustic metamaterials has received considerable promi-
nence due to the several unique properties found in this absorbers. AMM based on a microperforated panel of type

with internal air cavities have been promising and depending on the application provide satisfactory results at low
frequencies. This work investigates the performance of a honeycomb type acoustic metamaterial (AMM) modeled
as double-layered microperforated panels. The effective sound absorption in the frequency range between 100 and
500 Hz is verified analytical, numerical and experimentally. The analytical results are corroborated numerically

using a 3D finite element (FEM) method. A sound absorber sample was manufactured using 3D printing technol-
ogy and evaluated in an impedance tube considering the normal incidence of waves. Sound absorption of 94% at

182 Hz with a bandwidth of 52 Hz was obtained and good agreement with the analytical model was reached. In
addition, it is verified that this result is due to the high dissipation of sound energy in the perforation region of the
first panel. Therefore, this sound absorber shows excellent performance to control the low frequencies.