Abstract
Purpose
The computer performance is improving, and the various system optimizations by using the evolutionary computing are developed in recent years. Though the forms of large span roofs can be built free, the mechanical performances of the roofs are greatly different according to those forms. Moreover, though the aesthetic sensibility is demanded, the studies of morphogenesis which consider the aesthetic sensibility and mechanical rationality are little. We developed an idea support morphogenesis system that satisfies the designer's image and proposes the form with a high mechanical rationality, by using the Genetic Algorithm. However, the form that can be proposed by the existing research is limited in a symmetric form, and the proposed form does not have a guarantee that satisfies the designer's image. To solve these problems, and to develop a more effective system, the improvements of this study are as follows;
1) To enable the input of asymmetric form image
2) To propose Pareto solutions as two purpose optimization problem of “Image” and “Equivalent stress”, and to develop the system to which the designer can decide the final form.
3) To obtain the design knowledge concerning a morphological change necessary to improve the mechanical rationality.
Methods
The image of an old system was input by two directions (the direction of X and the direction of Y). In the new system, the complex forms are created by the image input for three directions (direction of X1, direction of Y1, and direction of Y2) or four directions (direction of X1, direction of X2, direction of Y1, and direction of Y2). The form is defined by control points of Spline curve. The form created by the image input is changed slightly by moving control points. This system creates various forms by changing the moving quantities of control points and proposes Pareto solutions of “image” and “mechanical rationality”. From the execution results, we analyze how the form is changing by differences of the moving quantities of control points.
Conclusions
By changing the control point magnification large, the equivalent stress became small though the image difference from an initial form became large. “Image” and “Equivalent stress” are in the relation of the trade-off. It became possible for the designer to select the form which satisfies both his image and mechanical rationality by proposing Pareto solutions. From an existing research, the design knowledge has obtained, that is, a mechanical rationality is improved when the curvature of form becomes a single curvature. From the execution result of model 1 and model 2, we could reconfirm this knowledge.
