Research On Vibration Calculation Method Of Rudder-Propeller Propulsion Shafting

With the development of world offshore oil exploration and exploitation scale, more and more offshore oil platform engineering ships will be needed to assist offshore operations. In order to adapt to bad weather of the sea and the needs of actual production operation, platform engineering ships must have good maneuverability and dynamic positioning performance. So the technology of rudder-propeller propulsion arises at the historic moment, more and more have been applied to this kind of ships, and then it has very broad application prospect. The propulsion system of rudder-propeller is distinct from the conventional propulsion systems. It has a small angle between shaft axis and hull baseline. Cross shaft type cardan, Bevel gear transmission mechanism, high flex coupling is adopted in the propulsion shafting. Propulsion shafting is very complex, so research on vibration characteristics of rudder-propeller propulsion shafting still is not perfected.According to special structure of rudder-propeller propulsion shafting, this paper makes the propulsion shafting of 78m DP2 offshore platform workboat as the research object, respectively adopts theory method and simulation analysis method to calculate and study on torsional vibration and swing vibration characteristics. Compared with the measured results, the feasibility of theory method and simulation analysis method is verified. It has important theoretical and practical significance to research on vibration characteristics of rudder-propeller propulsion shafting. The main research content are:1. The structure, the performance and the development history of rudder-propeller propulsion shafting are systematically discussed, the development condition of this research field is stated, and its research objective and research content is introduced;2. The analytical method and the transfer matrix method are adopted to establish the simplify system model of shafting, treatment processes of various exciting source are summarized, and torsional vibration and wheeling vibration calculation and analysis are carried out using MATLAB engineering calculation software;3. The multibody system dynamics and finite element method is expounded systematically, the simulation software is introduced, and the process of vibration simulation analysis is explained. The simulation analysis model of propulsion shafting is established, using 3d modeling software Pro/E, virtual prototype simulation analysis software ADAMS and finite element analysis software MSC/Nastran. And torsional vibration and wheeling vibration of propulsion shafting is analyzed;4. Compared with the measured results, the feasibility of theory method and simulation analysis method is verified.