Cold‐formed steel beam profiles for lightweight modular floor systems: A numerical study

Abstract

Modular steel buildings are increasingly utilised due to their rapid construction timelines and lower carbon footprint. However, transportation and lifting challenges associated with the high self‐weight of modules remain a critical constraint. Floor systems are estimated to contribute around 30% of the total module weight. This highlights the potential of reducing structural weight through optimised cross‐sectional shapes, such as lightweight cold‐formed steel beams (CFS) with improved flexural efficiency. This study numerically investigates the bending performance of various CFS profiles, including lipped channel (LC), lipped sigma (LS), and supersigma (SS), to evaluate their strength‐to‐weight efficiency. The cold‐formed beams are numerically simulated, and their performance is assessed using a two‐stage linear elastic buckling and nonlinear analysis, with the results validated against reported experimental data. The numerically obtained flexural capacities were used to assess the accuracy of Direct Strength Method, showing accurate strength predictions. In addition, results showed that the SS section, characterised by a modified trapezoidal web stiffener, exhibited approximately 18% and 20% higher capacity than the LC and LS sections, when compared at an equivalent coil length (constant weight).