Buckling behavior of cold-formed high-strength steel sections: Numerical insights and design implications

Cold-formed high-strength steel (HSS) offers practical advantages, like thinner cross-sections that reduce material costs. Recent research suggests these steel members may be more resilient than once thought, developing localized plastic deformations that improve resistance, even if they don’t behave like traditional ductile materials. However, design complexities persist due to insufficient research on buckling behavior in HSS cold-formed columns. A crucial factor that has not been widely explored is the impact of cross-sectional geometry, particularly the corner shape of square hollow sections (SHS), on their buckling behavior. This study investigates the buckling behavior of high-strength cold-formed steel square hollow sections (SHS) under axial compression, focusing on the influence of corner geometry, material properties, and section thickness. Finite element analysis conducted using Abaqus revealed that sharp-cornered sections demonstrate superior buckling resistance and higher ultimate axial loads compared to round-cornered sections, while the latter exhibit better post-buckling ductility. A parametric study highlighted the critical role of section thickness and corner radius in enhancing structural performance, with thicker sections and smaller radii showing increased resistance and reduced slenderness. Comparisons with Eurocode 3 revealed discrepancies, emphasizing the need for updates to account for the behavior of high-strength steel and complex geometries. The findings provide valuable insights for optimizing design practices, ensuring safer and more efficient structures, and advancing guidelines for high-strength cold-formed steel applications