Effect of X-Cable Bracing on the Optimized Weight of Planar Steel Frames Under Wind Load: A Parametric Study

In designing tall buildings, the primary concern is ensuring an effective lateral load-resisting system in addition to the gravity load system, since it largely governs the overall design. This study investigates the influence of X-cable bracing on the structural weight of tall steel frame buildings subjected to service and wind loading. Three numerical case studies, 10-story, 20-story, and 30-story planar steel frames, were modeled and analyzed using SAP2000, then optimized using Differential Evolution (DE) and Enhanced Colliding Bodies Optimization (ECBO) algorithms. These designs were evaluated under both service and wind load conditions, considering strength and drift constraints. The results indicate that the inclusion of wind loads in addition to service loads leads to a higher total structural weight than considering service loads alone, while cable bracing effectively reduces the overall mass by up to 6%, 38%, and 20% for the 10-story, 20-story, and 30-story frames, respectively, compared to unbraced structures, by improving the internal force distribution among structural components. Strength demands, reflected by the interaction ratio, governed all design cases, while lateral displacement was always less than the maximum limit according to AISC and ASCE requirements. Overall, the results highlight the potential of cable bracing systems to deliver efficient tall building designs; however, further studies are needed to generalize these findings to a broader range of building configurations.