Influence Of Acoustic Coating Damage On Sound Stealth Performance Of Hull

As the most active military force in the maritime battlefield,the acoustic stealth performance is an important indicator to evaluate its combat capability.The submarine will be subjected to environmental corrosion and explosion impact during long-term underwater service,resulting in surface acoustic coating shedding.It is of great strategic significance to explore the influence of coating damage on the invisibility of the submarine.In this paper,the influence of acoustic coverage area and form on acoustic parameters and sonar detection distance of underwater targets is discussed in detail.In this paper,the theory of the direct acoustic-vibration coupled finite element method based on the automatic matching layer is first expounded.The near-field acoustic pressure of the single-layer ring-stiffened cylindrical shell and the target strength of the elastic spherical shell are calculated,which are compared with the pool experiment and the analytical solution of the normal series to verify the effectiveness of the calculation method.Secondly,on the basis of the verification experiment of cylindrical shell radiated sound field,the effect of homogeneous rubber coating is considered to analyze the influence of adhesive area on the acoustic vibration response of cylindrical shell.In order to simulate the damage of coating layer in the cabin section of a real hull,the numerical method is further used to qualitatively analyze the influence of the rib section and the laying area of coating layer on the sound field and target parameters of the cabin section.In practical engineering,the acoustic tile usually contains periodic cavity in order to improve the acoustic vibration suppression,and it is difficult to establish a whole numerical model.Therefore,based on the layered medium theory,this paper studies the equivalent method of the coating,analyzes the influence of cavity shape and size on the sound absorption coefficient and obtains the parameter configuration scheme with the highest average sound absorption coefficient in the specified frequency band.On this basis,the sound field and target parameters of the hull under different damage degrees of the cover are further studied,and the damage ratio-target parameter function is fitted.Finally,the detection distance formula is derived based on the sonar equation,and the quantitative relationship between the detection distance of the enemy sonar to the ship and the damage degree of the acoustic coating layer of the ship is analyzed,and the graphical user interface of the sonar detection distance warning is designed.The research results of this paper have guiding significance for the research of hull damage assessment,and provide reference for the formulation of relevant standards.