The Research Of Far-Field Sound Radiation Of Double Ribbed Cylindrical Shell With Decoupled Material

The hiding is one of capabilities of submarine and it is very important to submarine. As the development of the anti-submarine detecting measure and weapons, people want the submarine to have an better function to hide itself, and only when the submarine is enough quiet it can avoid detecting by enemy. When activated by a harmonic force or a moment the submarine will induce steady vibration. This vibration will not only spoil working environment, disturb the instrument's working, but also induce radiation noise, which diffuses to air called cabin noise or diffuses to water called underwater noise, and it's the primary factor which influences the submarine's hiding function.Double cylindrical shells with stiffened ribs are major structure of cabin on the submerged or underwater vehicles. It is very important to study its vibration and sound radiation. This thesis mainly researches a submarine structure which uses the separating sound and decoupling material in different modes. We study its vibration and sound radiation by FEM and SEA and compare to model test. This thesis mainly includes:For the underwater ribbed double cylindrical shell's vibration and radiation, it set up a kind of vibroacoustic experiment model for the "structure-decoupled material-fluid " coupled action, and based on this model it performed a model experiment.Based on classical mode theory and by the FEM acoustic function, it sets up a FEM analyses model. Then it calculates the structure vibration and radiation by FEM software ANSYS and acoustic software SYSNOISE, and then compares with experiment.Because of the error of the FEM, it also analyzes the model vibroacoustic by SEA. Meanwhile, we discuss the effect to vibration and sound radiation about damping loss factor and interor loss, and then compares with experiment.