部材の断面積を考慮した配置最適化手法の大規模骨組み構造への適用

抄録

To design economical frame structures, it is necessary to determine the optimum frame layout and optimum cross-sectional area of each frame member. Although previous studies have proposed a variety of optimization methods, they can be applicable to small-scale frame structures and have been verified only for simple frame structures with a small number of design parameters. Therefore, it is desirable to develop an optimization method applicable to large-scale frame structures with a large number of design parameters. However, no studies have been conducted on an optimization method for large-scale frame structures. This study applies the layout optimization technique to determine both the layout and the cross-sectional area of each member for large-scale structures. In this method, to reduce the number of design parameters, first, only the existence of each member is determined in the layout optimization, and then, the cross-sectional area of each member is determined by the axial stress in the member, calculated through stress analyses. With the reduction of the number of parameters, the present method enables to determine the large-scale frame structures. To confirm the effectiveness, the method is applied to the optimization of a brace layout for a large-scale steel frame structure of a thermal power plant with about 250 design parameters. As a result of applying the method, the total weight of the obtained layout could be reduced by up to 17% from that of the existing layout. The results demonstrate that the method can be applicable to large-scale frame structures with hundreds of design parameters, such as steel frame structures in thermal power plants.