By considering the membrane's dissipation, the membrane-type acousticmetamaterial (MAM) has been demonstrated as a super absorber for low-frequencysound. In the paper, a theoretical vibroacoustic plate model is developed toreveal sound energy absorption mechanism within the MAM under a plane normalincidence. Based on the plate model in conjunction with the point matchingmethod, the in-plane strain energy of the membrane due to the resonant andantiresonant motion of the attached masses can be accurately captured bysolving the coupled vibroacoustic integrodifferential equation. Therefore, thesound absorption of the MAM is obtained and discussed, which is also in goodagreement with the prediction from the finite element method. In particular,microstructure effects including eccentricity of the attached masses, thedepth, thickness and loss factor of the membrane on sound absorption peakvalues are quantitatively investigated.
展开▼
