抄録
In this paper, the structural morphogenesis examples for free-surface grid shell with member of uniform length and joint angle are indicated. The building for a free-form surface grid shell structure of a magnificent and dynamic design became realizable from the confirmation of a structural rationality and the improvement of a construction technology. However, the constraint for a productivity and a workability of their structures produces in length of structural members and joint angle. In structural morphogenesis, it is important to use decent solutions that can be constructed with comparatively high evaluation including a global optimal solution (pareto optimal solutions), local optimal solutions (local pareto optimal solutions). The standard genetic algorithms (SGA) and strength pareto evolutionary algorithm 2 (SPEA2) are adopted with the structural optimization problem in order to obtain a global optimal solution and pareto optimal solutions, respectively. Genetic algorithms with immune system (ISGA) for a structural optimization procedure that implemented a manipulation of the decent solutions search is already applied to the structural morphogenesis for the grid shell.
In the numerical examples, the decent solution forms of the analysis model for the symmetric grid shell structure on an in-plane rectangular geometry are shown. First, we indicate the geometric relationship and computational procedure for creating the free-form surface using the forward kinematics and inverse kinematics when the structural members are set to a uniform length and joint angle. Next, we apply this technique to the structural morphogenesis for a grid shell with the single- and multi-objective optimization problem. The objective functions are the total and the bending strain energy and the volume of interior space. Finally, the structural properties of decent solution forms obtained by ISGA are presented.
