Research And Developing Of Ship Shafting Alignment, Whirling And Longitudinal Vibration Calculation Software

The propulsion shafting is the vital part of the marine machinery. The reasonable shaft design is very important to the long-term and reliable running of the propulsion shaft. Because it can not only reduce the repairing and maintenance expenditure, but also save the time and money lost in plant shut down and lower running. At present, Shafting alignment and vibration calculation program used at home is mostly rented or purchased from foreign companies. So it is of greatly significance for us to develop an independent program.In this article, the model and algorithms of the shaft alignment and longitudinalvibration and whirling vibration calculation are researched. On the base of theimproved algorithms, "Retsina Shaft Calculation program excels other programs, suchas Compass Shaft Alignment and Nautics Shaft Alignment respectively used by CCS( China Classification Society ) and DNV ( Det Norske Veritas ) .Then, "Retsina Shaft Alignment and vibration calculation software based on the Microsoft COM technology has been developed. The "Retsina Shaft calculation software application consists of a mathematical part (Matrix VB), a GUI part (Visual Basic 6.0) and a database part (Microsoft SQL). The program has been tested by comparing with shaft reports made by the ship classification society (CCS, ABS ( American Bureau of Shipping ) and DNV ) and the world famous companies (Kamewa and Man B&W). The performance of the program is excellent.At last, the shaft alignment considering the oil-film influence and the strain-gage method to check the installation of the shaft are discussed. Compared all the installation checking methods, the advantages of strain-gage method in working out the installation checking are described. It can constantly check the shaft state along with the change of the rigidities. On the basis of the measured strain, it develops a Riccati matrix method to check the strain of the shaft and the bearing reaction, as to satisfy the requirement of the shaft alignment by the iterative method.