In response to the problem of low-frequency noise prevention and control,a membrane-type acoustic meta-material is designed in this paper.By introducing the asymmetry of the mass block's structure,new vibration modes have been formed in the low-frequency range and the noise has been effectively controlled in the low-frequency range.The designed structure of the unit cell has four perfect absorption peaks in the range of 200～1 000 Hz,and the bandwidth of the absorption coefficient above 0.56 reaches 350 Hz,while the average absorption coefficient rea-ches 0.53.The geometrical parameters of the thin-film metamaterials have been further optimized and the supercell structure has been constructed to realize the acoustic siphon effect.While increasing the number of units with differ-ent resonance frequencies,the structure shows a better compatibility with the air impedance,the sound absorption peak reaches 10,the maximum sound absorption coefficient is 0.983,and the average absorption coefficient reaches 0.781 in the studied low-frequency broadband range,which effectively broadens the sound absorption range of the film metamaterial structure.This study enhances the low-frequency sound absorption effect of acoustic metamateri-als,providing a solution for improving the low-frequency sound absorption effect of acoustic metamaterials in struc-tural optimization design.
维普
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