Study on transverse vibration characteristics of the coupled system of shaft and submerged conical-cylindrical shell

Abstract

In the uneven flow field, the propeller excitation is transmitted to the hull along with the propulsion shaft system, which is the main exciting force that causes the structural vibration of the ship. A dynamic model to study the transverse vibration of the coupled system of the shaft and submerged conical-cylindrical shell was developed using an analytical method. Flügge equations of motion and beam theory were used to describe the motion of the shell and the shaft, respectively. The boundary conditions and continuous conditions of the shaft and the shell were given. Continuous conditions of the shaft and the shell were established at the bearing joint. The accuracy of the model was verified by FEM/BEM. The effects of fluid, excitations and bearing stiffness on the transverse vibration characteristics of the coupled system of the shaft and submerged conical-cylindrical shell were discussed. The results showed that bearing stiffness has a great impact on the transverse vibration of shaft and hull and make their vibration tend to be consistent when it increases.