Optimum Shape Design of Space Structures by Genetic Algorithm

Abstract

Space structures are usually highly indeterminate and therefore have a large number of redundant members. It is important to choose the appropriate number of elements and joints for the structure under consideration. Optimum shape design of space structures is the aim of the present work and to achieve an optimal configuration, parameters such as number of joints, number of members, support conditions and the overall shape of the structures are considered. To attain a practical configuration, the presence of the joints of the structures and the locations of the columns are taken as the shape design variables as well as the cross-sectional area of the elements of the structures under considerations. The resulting configurations are very interesting after the removal of unnecessary joints and columns. It was also observed that a part of sphere might not be appropriate for the dome structures as usually chosen by the designers. For different static loading conditions that presented in this research, second or third order polynomial would be more suitable for the shape of these structures. In this study, optimum shape design of space structures is performed using a modified genetic algorithm (MGA).