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.