| Recently,with the deepening of the national strategy of pursuing the dream of deep blue,the requirements for marine equipment are higher and higher.Submarine is important naval weapons and equipment,the requirements for underwater stealth performance of submarines are also increasing.Its stealth performance will directly affect the submarine’s own safety and the completion of strategic tasks.As one of the main echo highlights of submarine,the research on underwater acoustic characteristics of the submarine sail will be an important means to improve the underwater stealth performance of submarine.In this paper,the acoustic FEM is used to explore the acoustic characteristics of the basic unit grillage structure and the submarine sail underwater.Application of composite materials is one of widely used methods,which can strengthen the acoustic properties of structures.In this paper,the underwater acoustic characteristics of steel grillage structure,composite materials grillage structure composed of carbon fiber,glass fiber reinforced plastic and buoyancy materials and steel submarine sail,composite materials submarine sail are studied.In this paper,the vibration and acoustic radiation performance of the grillage structures with different materials,such as steel,carbon fiber and glass fiber reinforced plastic,were compared and analyzed,including the dry and wet modes of different materials,the vibration and acoustic radiation performance at the intersection of stiffeners and the center of panel under unit harmonic force excitation,and the reflection coefficients of three different materials.The effects of different materials were studied to find better composite materials.The modal and vibration characteristics are verified by experiments.For the submarine sail structure,the wet modes of steel structure and composite shell are compared and analyzed under natural state.The vibration and acoustic radiation properties of the stiffeners and the center of the plate under the unit harmonic force excitation,and the acoustic scattering characteristics calculated by the joint method of transmitting and receiving are analyzed respectively;the vibration characteristics and acoustic radiation characteristics of the two kinds of materials are compared and analyzed under the fluid load excitation state. |
