Research On Array Acoustic Structure’s Influence Of Acoustic Signal’s Propagation

Acoustic metamaterial refers to a specially designed acoustical novel material or new structure that is periodically arranged by artificial acoustic structural unit in a matrix material,so that it having extraordinary physical properties that are different from those in nature.Acoustic surface structure is a kind of two-dimensional acoustic metamaterials.The distribution and size of units in the periodic array structure influence the propagation of acoustic waves,resulting in changes in the path of acoustic wave propagation.The acoustic micro-structure metamaterials designed at specific scales can realize local resonance and sonic convergence of the waves in the microstructure region.This phenomenon can be applied to acoustic stealth or acoustic detection.A large number of theoretical and experimental studies by previous researchers have shown that reasonable design of parameters such as the size of the unit structure in the acoustic surface structure can make the acoustic surface structure regulate the acoustic wave propagation path.The main research content of this paper is to carry out periodic microstructure design on metal structures.Through the finite element multiphysics simulation software,the influence of acoustic wave propagation is studied in detail from the aspects of the number,size,period of the defects in the structure and the frequency of the signal source.Through the analysis of the simulation results,the appropriate defect structure parameters and signal parameters are selected so that the acoustic signal of a certain frequency can be coupled with the acoustic surface structure during propagation,and the effect of local resonance of the sound source signal can be obtained.Finally,a systematic experiment of the acoustic surface structure was performed to verify the accuracy of the simulation results.Through the analysis of the simulation results,it is found that changing the size,number,and period parameters of defects in the acoustic surface structure can indeed affect the acoustic wave propagation path.The more the number of defects,the more energy can be concentrated in the defect area of the structure,that is,the specificity of acoustic metamaterials can be more reflected.When the hole defect radius is about 0.1cm,the period is in the range of 0.4~05cm,and the frequency of the sound source signal is about 3.5MHz,it can make the sound wave form an obvious local resonance effect in the sound array structure.Acoustic surface structure can be used in acoustic stealth,such as acoustic stealth of unmanned submersibles and submarine equipment.