19 巻 (2014) p. 149-157
A structure optimization of mid-ship section is under consideration in this paper. A double hull oil tanker is selected for the target of optimization. Since there are many design variables in the mid-ship section, usually, design variables are divided into some groups in the viewpoints of designing and the manufacturing. When the classification of design variables is not proper, there is a problem that the optimal solution cannot be obtained. In order to overcome this drawback, a classification method of design variables is proposed here. Influences of design variables to constraint conditions are estimated based on principle component analysis and used for classifying design variables. The classification of design variables obtained by the proposed method is different from a conventional group. The selected problems by use of the proposed method are solved, and it is shown that the proposed method can give us a better solution than the conventional method.