Study On The Design And Adjustability Of Thin Film Acoustic Metasurface

When the propagating sound wave passes through an obstacle,a series of processes,such as reflection,transmission and energy loss,will occur,leading to the reduction of sound energy.We call this process sound insulation.Due to the effect of mass law,it is very difficult for traditional materials to isolate lowfrequency noise,while acoustic metamaterials break the limit of mass law,realize small-scale control of large wavelength,and effectively control low-frequency acoustic waves.In this paper,the sound insulation mechanism of thin film acoustic metamaterials(composed of thin film and mass block)is analyzed,and the propagation principle,sound insulation evaluation mechanism and film vibration of sound wave are studied.The influence of different parameters on the sound insulation performance of thin film acoustic metamaterials is studied by simulation.Through the simulation experiment of membrane size and prestress,it is found that the influence of membrane size on the sound insulation effect is significant,and the scale effect is obvious.In this paper,the scale effect of thin-film acoustic metamaterials is further studied,and the absorption of low-frequency sound wave is realized by reducing the size of thin-film.In view of the fact that the circular film is not conducive to the tight arrangement,the polygonal film design and research are carried out,and the hexagonal honeycomb structure film acoustic metamaterials are mainly studied.A new type of film type acoustic metasurface is proposed to improve the sound insulation effect of low frequency and wide frequency.In this paper,the inside and outside diameter ratio of the new type of acoustic hypersurface is analyzed,simulated and calculated,and the corresponding experimental scheme is put forward for verification and analysis.Compared with the experiment,the simulation results fit well and verify the accuracy of the conclusion,which has engineering application significance.In this paper,we study how to further improve the sound insulation bandwidth of thin-film acoustical metamaterials,propose a kind of laminated thin-film acoustic metamaterials,and analyze its sound insulation characteristics.At the same time,the sound insulation properties of the film type and the spiral type are compared.