Influence of depth and cavity shape on absorption coefficients of sound-isolating decoupled tiles

An analysis of underwater sound absorption structures made up of non-uniform multilayer damping boards.The transfer matrix of sound-isolating/decoupled tiles with cavities,and the surface absorption coefficient of multilayer structures were derived based on wave-guide theory.The deformation of decoupled tiles with cavity structures by hydrostatic pressure was calculated by Ansys software.Finally,the relationships between the sound absorption coefficient and hydrostatic pressure and cavity shape are obtained for the sound-isolating/decoupled tile with cavity.The results show that the shape of cavities has a great impact on sound-absorption capacity.With increasing depth,the absorbing capacity of sound-isolating/decoupled tiles drops in the low frequency zone.So,in practice,the influence of hydrostatic pressure can not be ignored.