Topology Optimization of Steel Braced Frames to Achieve Minimum Weight and Maximum Collapse Resistance

Abstract

This research proposes a topology optimization strategy for steel braced frames to reduce overall structural weight while maintaining strong resistance to progressive collapse. The approach combines performance-based design concepts with the Alternate Path Method (APM) to examine structural robustness under sudden column removal conditions. Nonlinear finite element models are developed to perform both static and dynamic analyses, enabling evaluation of load redistribution, development of alternative load paths, and energy dissipation behavior following localized failure.

The optimization procedure determines the most efficient arrangement and distribution of bracing members that achieves material efficiency without reducing collapse resistance. Findings indicate that the optimized bracing configuration significantly lowers structural weight while preserving, and in some cases improving, global stability and robustness. The proposed framework provides a practical and economical solution for designing steel structures capable of withstanding accidental or extreme loading events.