Evaluating the Seismic Response of CFS Strap-Braced Walls with Optimised Sections

Abstract

Cold-formed steel (CFS) profiles are widely used in light steel-framed buildings, particularly for low- to mid-rise construction, where CFS strap-braced frames serve as key lateral load-resisting systems. This research focuses on the seismic performance of strap-braced walls incorporating CFS members, with a particular emphasis on optimising stud elements to function efficiently as beam-columns. A typical cross-section, derived from commercially available profiles, is selected and refined to maximise structural capacity while adhering to industry standards and practical limitations. Finite element (FE) models are developed for two strap-braced wall frames, where the sections are used for both the studs and chords: one frame uses commercially available CFS sections, while the other employs optimised sections aimed at enhancing seismic performance. While conventional designs include gravity loads, they often overlook P-Δ effects; this study addresses that limitation by applying different axial compression levels to assess the impact of P-Δ effects on both developed models. The structural performance is evaluated based on lateral drift compliance and the avoidance of premature failure caused by P-Δ effects in the chord studs. The outcomes offer valuable insights for enhancing the seismic design of CFS structures, presenting a systematic optimisation strategy that improves ductility, reliability, and structural integrity under seismic loading.