Experimental Behaviour of Cold‐Formed Stainless Steel Cruciform Section Columns

This paper describes experiments addressing the buckling and collapse behaviour of cold‐formed stainless steel cruciform section columns. To build doubly symmetrical flanged cruciform section columns, six individual press‐braked plain channels made of austenitic grade EN 1.4307 were assembled back‐to‐back. Two channel geometries were used – with cross‐section height 200 mm and 100 mm. They were connected using bolts M8 of class 8.8, with equidistant spacings along the column length. Six columns with three different lengths – namely, short (600 mm), intermediate (1200 mm) and long (2400 mm) – were tested under pure axial compression load and under end semi‐rigid support conditions. Two tests were included for each length. It was observed that the buckling patterns in the built‐up cruciform section specimens were affected by their global slenderness and by the spacing between the fasteners. However, in the cases of long specimens, where global torsional buckling was critical, the fastener spacing had a minor influence on the ultimate capacity of the columns.