The Research On Vibration And Sound Radiation Characteristics Of Submerged Composite Plate Structure

Most of modern ships are composed of the plate structure and composite plate structure.The floor of the ship is excited by the flow-induced, mechanical, propeller and so on, isbecoming one of the more serious areas of noise and vibration.This thesis is based on finite element and boundary element method, and combined withboundary element software to study the plate and composite plate’s vibration and acousticradiation characteristics.Firstly, by using ANSYS and SYSNOISE to research the modal and harmonic responseof simply supported rectangular plate in air and water, and then studied the influence of itsvibration and acoustic radiation by adding infinite baffled and stiffened. When studies thesimply supported circular plate’s vibration and acoustic radiation underwater, gain theinfections by adding the finite baffles.For rapid predicting of the plate and composite plate’s vibration and radiated sound fieldin the semi-infinite waters, by using APDL language for the interface of ANSYS, to storeeach node’s sound pressure and vibration displacement of the surface of structure, and thenuse boundary element software to calculate the acoustic radiation power. When analysis of thesimply supported plate’s sound and vibration characteristics, gain the infections of differentstructure damping; by comparing the damping layer and its thickness, damping factor andYoung’s modulus and other parameters, gain the infections of the free damping layercomposite plate’s sound and vibration characteristics; When analysis of different plate’smaterial sandwich plates and multi-layer composite plates, its vibration and sound radiationcharacteristics are discussed.Finally, according to the simulation model, the rectangular plate model has been built up,and the radiated power of the model has been measured by reverberation method in reverbpool. By comparing the result of experimental measurement and numerical calculation showthat the reverberation measurement for underwater acoustic radiation is an effective method.