Development and Application of Three-Dimensional High-Degree-of-Freedom Multiobjective Design Optimization Method

抄録

A global multiobjective design optimization method for three-dimensional design optimization based on topology optimization is presented. The proposed method employs a technique that compresses three-dimensional images using octree for encoding to reduce the number of design variables and improve optimization efficiency. The resulting octree structure is optimized through evolutionary algorithm with operators inspired from genetic programming. To validate the proposed method, an optimization problem to reproduce the target shape is solved. The results demonstrate that the proposed method effectively captures design features with a minimal number of solution evaluations. Furthermore, to validate the efficacy of the proposed method for aerodynamic design optimization problems, a design optimization of wingtip design for micro aerial vehicles is presented. It is confirmed that the proposed method can reproduce various geometries. The non-dominated solution obtained captured the trade-off relationship between the two objective functions. In addition, the non-dominated solution exhibited a lift coefficient improvement of up to 55% and a drag coefficient reduction of up to 2% compared to the baseline design. Geometry and aerodynamic performance revealed cant-up and cant-down shapes specific to the design conditions.