Research on Bracing Layout Optimization of High-Rise Steel Frame Structures Based on ESO and Conceptual Design

The form of the bracing layout in braced steel frame structures plays a critical role in determining the lateral stiffness and seismic performance of the structure. This paper proposes a topology optimization method for designing the bracing layout based on Evolutionary Structural Optimization (ESO) and conceptual design principles. Different possible bracing layouts can be described as a string of binary codes where ‘0’ and ‘1’ indicate the absence or presence of a bracing unit, respectively. The bracing layout state is classified according to the structure’s eccentricity, while the internal force of the bracing is adjusted according to the importance of the bracing and the symmetry of the structure, and the bracing units with a small contribution to the structure are gradually removed. Subsequently, an optimization program is employed to minimize structural weight considering multiple loading cases and constraints. The automatic optimization program was successfully applied to optimizing bracing layouts for two different steel frame structures. The results demonstrate that this bracing layout optimization method for high-rise steel frame structures, based on ESO and conceptual design, achieves a reasonable arrangement of bracing and reduces the steel consumption of the structure, which proves its feasibility and effectiveness.