抄録
A new and direct topology optimization method of generation for rib layout pattern so called as growth technique is proposed in this paper. The method suggests that the ribs extend from the ground structure just like branches of tree grow from seed or trunk, so it should obey a certain growing and branching rule like tree. The initial growth points, so called seeds, are specified in advance, and baby ribs around seeds on the ground structure have the ability to grow along the grid nodes of finite elements by taking into account their design sensitivities. The potential ability of branching will be assigned to the ribs greater than the specified threshold dimension. During the growing process of rib, the volume growth rate is controlled so as to be possible to create new branches and to eliminate degenerated ribs. The stop condition of the growth process is that the rib volume reaches the given upper limit value. The validity and effectiveness of the suggested method is confirmed by the numerical results of some typical rib layout design examples, and optimal patterns of rib layouts for square plates under different combinations of loads are demonstrated.