Metaheuristic Optimization for the Performance-Based Design of Steel Concentrically Braced Frames

Structural engineers aim to design buildings that perform reliably during earthquakes. Performance-based design (PBD) is a powerful approach that minimizes damage and enhances safety. This study investigates an optimal PBD for two-dimensional 3-story and 6-story concentrically braced steel frames (CBFs), achieving suitable seismic performance while minimizing weight and cost. The optimization problem is formulated to minimize the structural weight. The acceptance criteria from ASCE41-17 for linear static analysis of CBFs have been used to define the problem constraints. The geometric dimensions of the connections, interstory drift, slenderness ratio of the columns and braces, and demand-to-capacity ratio of the members have been considered as design constraints. The optimization problems have been solved using the enhanced vibrating particle system (EVPS), water evaporation optimization (WEO), and gray wolf optimization (GWO) algorithms. The results indicated that the EVPS was more capable of finding the optimal solutions and demonstrated more consistent performance. It also demonstrated a shorter execution time compared to the WEO and GWO algorithms. It could be concluded that solving the weight optimization problem of CBFs based on PBD using these metaheuristic algorithms is feasible and that acceptable solutions can be obtained in less time using the presented approach.