An Integrated Shape Optimization Method for Hybrid Structure Consisting of Branch and Free-Form Surface

Abstract

Branching and free-form structures are widely used in large-span buildings. Their shapes are the main factors that affect their mechanical performances. Many studies have been carried out on the morphology of single structural systems, but less on hybrid structures. However, both of them often appear in the same building. In order to reflect the cooperative bearing of substructures in the optimization process of branch-supported free-form surface structures, this paper proposes a holistic shape optimization method. The proposed method extracts design variables based on the structural modeling process, and uses the coordinates in the parametric domain to realize a mathematical description of the positional relationship between substructures. Then, the sensitivity analysis method is used to adjust the position of design variables to reduce the overall strain energy, realizing the integrated shape optimization of this hybrid structure. The effectiveness of the method is validated through several numerical examples. The results show that the overall stiffness of the optimized structure has been significantly improved, and the process of integrated optimization is more convenient. Furthermore, the way of adjusting design variables directly affects the shape and mechanical performance of the optimized structure. This feature serves as a valuable design tool that can provide multiple feasible solutions for architectural and structural design.