Structural Design And Experimental Study Of Three-dimensional Acoustic Metamaterial

Acoustic metamaterial is a new-type material which has been developed in recent years.Acoustic metamaterial is expected to be widely used in noise control,vibration isolation and the design of new wave-guide devices.One of the current research directions of acoustic metamaterials is to design an acoustic metamaterial with a wide frequency band gap and a good sound insulation effect.Judging from the existing research,the band gap of three-dimensional acoustic metamaterials is higher than that of two-dimensional and one-dimensional acoustic metamaterials,and the acoustic performance of membrane-type acoustic metamaterials is superior.Therefore,this paper combines the two structure to design a structure of the three-dimensional frame coating membrane can have a very wide sound insulation band and a low sound insulation frequency.In order to be able to apply the structure to the actual life of the application,we discuss the material parameters and geometric parameters of the structure based on the energy band theory.Combined with experimental verification and finite element analysis,we proved the accuracy of the calculation.Firstly,based on the energy band theory,the structural intrinsic modes are analyzed,and the three-dimensional acoustic metamaterial is structurally designed and analyzed.In terms of structure,the size of attachments,frame thickness,and film thickness were determined.In materials,the influence of structural material distribution and other factors on the structure band gap was studied.In addition,due to the large amount of structure attachments,the study also performed on attachments.Hollow treatment to study the influence of this structure on the band diagram.In order to be able to better put the structure into practical applications.Then,using the sound insulation theory of single-layer media and multi-layer media to perform sound insulation analysis on the completed structure,the correctness of the above energy band theory can be verified.In addition,according to the relationship between size and frequency in the energy band theory,Stacking different sizes of original cells results in a wider sound insulation band.Because the structure is a closed structure,the pre-stress applied in the interior will have a greater impact on the sound insulation effect and achieve the tunability of the sound insulation.Finally,in order to verify the accuracy of the previous calculations,it was demonstrated that the acoustic metamaterials studied in this study have good sound insulation properties.In this project,a three-dimensional acoustic metamaterial was manufactured based on a simulation model.The sound isolation test was performed using the reverberation room method to obtain a three-dimensional acoustical material’s sound insulation curve.The results are in good agreement with the results of the finite element analysis and the forbidden range.It is a good example to verify the acousticproperties of the studied acoustic metamaterials and provide reference for future applications.