Study On The Absorption Characteristics Of Anechoic Tile With The Method Of Transfer Function

Anechoic tile equipped on the surface of the submarine is an acoustic component,which can make the submarine invisible for its sound absorption.The basic structure of anechoic tile is a rubber plate,the structure of which has been improved gradually with the increasing demands for the perfect properties.Now the most general structure of anechoic tile is the rubber plate with holes to improve its ability of sound absorption.The sound absorption principle of anechoic tile is detailed in this paper from the acoustical theory.Rubber is the most widely used sound-absorbing material for its remarkable physical and chemical properties.It is important to improve the structure as well as to choose the appropriate material to improve the sound absorption of anechoic tile.Within the rubber, small volume deformation near the cavity caused by the incident longitudinal wave can result in big shearing deformation,i.e.the waveform changes leading to bigger loss of the sound energy and better absorptivity.Therefore, increasing the shear wave within the rubber is the first choice to improve the structure of the anechoic tile.The sound absorption of the anechoic tile is researched by the transfer function method,the basic theory of which is detailed firstly.And then two different computation models and several verifying examples are given accordingly.Finally, the appropriate material chose is set by the calculations, and the influences of the parameters of the material,the shape of the cavity on the absorption property,as well as the influences of the layer, model on the calculation results are analyzed.