Analytical Method Of Fluid-structure Interaction On A Structure Subjected To Underwater Explosion With Acoustic Tiles

With land resources increasingly drying up, the sea has become the development priorities for each country. And submarine is one of the most powerful weapons to maintain their maritime rights and interests and safeguard national security. With the development of sonar detection technology, there is a greater demand for submarines which possess excellent acoustic stealth performance. Covering the surface of submarines with stealth material is one of the most important methods which are widely adopted so as to improve acoustical stealth performance and help submarine better survive from modern sea battles.Submarine,performing as a platform for various kinds of combat equipment, is more likely to suffer attack from all kinds of anti-ship weapons such as missiles, torpedoes, naval mine, aero bomb and so on. While most of the acoustic layers is made of viscoelastic material and contains cavity structure of special form, it will inevitably cause deformation to the structure of the coating layer when it is subjected to underwater explosions, which helps absorb the energy emitted by underwater explosion shock wave and thus has an impact on the anti-blasting performance of submarine structures.In this paper,the frequency domain method is utilized to explore the laws of reflection and transmission of shock wave energy in rubber-water and rubber-steel interface and study the effect of material parameters of acoustic tile. Research shows that the amplitude of transmission impulse is unrelated to the material parameters of acoustic tiles. And the structures only change the transmitted wave form and reduce the speed of the impulse loading. The impulse peak is mainly related with the relative impedance of the liquid in the front of and behind the structure.In order to get the dynamic response of the structure with acoustic tiles subjected to underwater explosion, acoustic wave equation is adopted to modify the early period of DAA and the engineering approach is established. Then the tests in which the steel plate and stringerstiffened cylinder covered with acoustic tiles are subjected to underwater explosions are carried out to validate the frequency domain method based on wave theory and the modified DAA method. Besides, the effect of hydrostatic pressure and impact factors on the explosion response is analyzed.