Research On Torsional Vibration Mechanism Of Complicated Marine Propulsion Shafting And Calculation Software Development

With the fast development of national shipbuilding industry in recent years, many new types of propulsion system appear constantly. Some of them are very complicated. Although the basic theory of torsional vibration is quite mature, however, there is a big difference between the complicated marine propulsion shafting and the straight chain propulsion shafting. More factors involved in the calculations, and thus the vibration mechanism is more complex. The torsional vibration of ship propulsion shafting is related to the operational safety of the ship. Therefore, the torsional vibration issues of complicated marine propulsion shafting are promoting more and more attentions. Understanding the mechanism of torsional vibration of complicated marine propulsion shafting and developing highly integrated, modular, structured and precise calculation software on torsional vibration seem to be more and more important.In this paper, a series of theoretical issues involved in the torsional vibration of complicated marine propulsion have been research on based on the normal torsional vibration theory of marine propulsion shafting. Based on the research results, having used GUI Design Studio as the UI design tool, Visual Studio 6.0 as the development environment and used database technology and XML technology to build the data system and having promoted the development of torsional vibration calculation software of complicated marine propulsion shafting and verified by examples and tests. The main research activities include:1. Made a summary of the types of ship propulsion shafting, introduced the basic theory on torsional vibration of marine propulsion shafting, and made a summary of the advantages and disadvantages of each method.2. Made a research on the calculation method of the excited torque introduced by the diesel. Introduced the Indicator Diagram Method, Simulated Indicator Diagram Method and the Experience Formula Method. Made a research on the non-uniform character of the load acting on cylinders and gave the basic calculation method on it.3. Introduced the basic calculation method of the propeller excited torque. Made a summary of the values of the propeller excited torque ratio in the empirical formula. With the combination of past experience, gave a range of reasonable value of the propeller excited torque ratio.4. Made a research on the problem of power distribution and gave the handing method of the two conditions which occur during the actual calculation process. Analyzed the characteristics of the propulsion shafting and the calculation method of the secondary excitation induced by the cardan joint were studied in detail. And the corresponding approach was given. Studied the problem of torsional vibration damping, summarized the various damping methods and formulas.5. Using GUI Design Studio as the UI design tool, Visual Studio 6.0 as the development environment and using database technology and XML technology to build the data system, having promoted the development of torsional vibration calculation software of complicated propulsion shafting and verified by examples and tests.