Material Ductility and Buckling Behaviour of Eurocode‐compliant Cold‐formed Steel Hollow Columns

Abstract

Square and rectangular cold‐formed hollow sections are generally produced by either direct forming or indirect forming. These methods allow manufacturing nominally similar geometries of the cross‐sections, but leading to some different mechanical characteristics. The present paper addresses cold‐formed structural hollow sections produced by indirect forming that are characterized by the greater residual stresses, focusing on (i) the ductility of the cold‐formed material in the corners and flat parts of the section; (ii) the reliability of the buckling curves given by EN1993‐1‐1 for this type of columns. The reliability assessment is performed using first order reliability method on a detailed and validated numerical model developed in OpenSees. The results show that the current curve “c” in EN1993‐1‐1 underestimates the buckling capacity of stocky members.

State-of-the-Art: Integrating Fastener Technology and Design Guidelines for Enhanced Performance of Cold-Formed Steel Sections

“…The presence of holes in the webs of these members serves various purposes, such as facilitating the passage of utilities like electrical wiring, plumbing, or ventilation systems. Furthermore, these holes can reduce the overall weight of the member while maintaining its structural integrity [2,20,21].…”

“…When designing CFS elements with hollows in the webs, careful consideration of factors such as load-bearing capacity, the distribution stress, and the holes' impact on the overall stability of the structure is required. To ensure the safe and efficient use of such members, industry standards and guidelines provided by organizations like (AISI) or the International Code Council (ICC) outline specific criteria and design methodologies [2,20,21].…”

“…By incorporating holes in the webs of thin-walled elements, engineers and architects can optimize their designs, improve installation efficiency, and enhance the functionality of the overall structure. Additionally, this approach allows them to adhere to industry standards and regulations, ensuring the structural integrity and safety of the construction project [2,20,21].…”

“…Reduced Ductility: Sections made of cold-formed steel generally exhibit lower ductility as compared to sections made of hot-rolled steel. This reduced ductility may limit their ability to absorb energy during seismic events or high-impact loads, requiring careful design and detailing to ensure structural performance [20,64,65].…”