Acoustic And Anti-shock Capability Research Of The Acoustic Layer Structure

The submarine's hiding function attracts much of people's attention all the time. The noise of such structures roots in the shell vibration that drove by the inner engine, when coupled with the liquid medium, the noise will affect the performance of the vessels badly. Finite cylindrical shells with stiffened ribs are major structure of cabin on the submerged or underwater vehicles. And coating all kinds of acoustic cover layers on the shells is the most common and very effective method in decreasing the submarine sound radiation. The distortion circs under hydrostatic-pressure and anti-shock performance of acoustic covering layer are studied, and these are significant for the design of acoustic covering layer. Meanwhile, this paper also studies the influence of structural stress parameters of different rib number on radiation noise of ribbed cylindrical shell. It mainly includes:Firstly, based on heterogeneous wave-guide theory, the acoustical of acoustic covering layer is studied, and the transfer matrix of isolating-sound and decoupled tile with cavity and surface sound absorption coefficient of multilayer structure are worked out. And the distortion circs of decoupled tile with cavity structure under hydrostatic-pressure is solved by the software ANSYS. The sound absorption coefficient of the acoustic covering layer along with hydrostatic-pressure and cavity change is worked out.Secondly, this paper researches on the energy absorption capability of plate-frame structure coated with acoustic layer, find relationship between structure's distortion, velocity, acceleration and energy absorption capability, get the structure's anti-shock capability, and optimize it. Based on this, the paper also provides some suggestions about design and performance parameters of structure coated with acoustic layer, which has both shock resistance and vibration isolation.Thirdly, the effect of structure styles of ribbed cylindrical shell the on sound radiation is discussed. The models of cylindrical shell of different structural parameters are built by the software ANSYS, then this paper calculates coupled vibration response of the models under vibrating force. It also calculates different acoustics physical parameters in software SYSNOISE, by using the displacement of structural surface as BEM boundary conditions, and gains the influence rules of structural stress parameters of ribbed cylindrical shell on radiation noise. The result of influence analysis of different structural stress parameters of different rib number on vibration and structural acoustics radiation has reference significance for structure design of cabin segment and controlling vibration and noise.