In this Paper, an intelligent hybrid Taguchi-genetic algorithm (IHTGA) approach is proposed to search optimal bearing offsets of shafting alignment for the vessel propulsion system. Its objectives are to minimize the shaft normal stress and shear force. Its constraints include permissible reaction forces and stresses of bearings, and shear forces and bending moments of the shaft thrust flange at operation conditions, which mainly contain cold and hot conditions. As well know, the correct alignment of the shafting system for main propulsion system is important to ensure the safe operation of a vessel. In order to obtain a set of acceptable forces and stresses for bearings and shaft at operation conditions, a set of optimal bearing offsets to be determined. However, instead of usually carried out on a time-consuming trial-and-error procedure in most of shipyard, the IHTGA approach is applied to search for the above bearing offsets. The IHTGA is to combine traditional genetic algorithms (TRGAs) with Taguchi method. Taguchi method is inserted between crossover and mutation operations of TRGAs. Then, the systematic reasoning ability of Taguchi method is incorporated in the crossover operations to intelligently select the better genes to achieve crossover, and consequently enhance the genetic algorithms. Therefore, the IHTGA can be more robust, statistically sound, and quickly convergent. Its fitness function is assigned as a pseudo objective function, which is a linear combination of design objectives and constraints by penalty function method. At the same time, the bearing reaction forces and stresses, and the shaft normal stresses, bending moments and shear forces become determined by using finite element method. The computational experiments show that the proposed IHTGA approach can significant reduce alignment time and improve performance as compared with trial-and-error result for 2200 TEU container vessel.
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