Numerical assessment of stainless steel starred rolled angle sections under compression

Abstract

This paper shows a numerical investigation of short-to-intermediate austenitic and duplex stainless steel welded starred columns with fixed supports prone to failure by torsional buckling. A finite element model, developed by the same authors in prior work and validated against experimental results, was used (i) to assess the cross-section geometrical properties – secondary warping and torsion constants, (ii) austenitic and duplex stainless steel material mechanical properties, (iii) the elastic buckling behaviour, and (iv) the columns' ultimate resistance. A parametrical analysis was carried out through a broader coverage of cross-section dimensions and member lengths. Finally, the obtained ultimate strengths are used to evaluate if the Eurocode 3: Part 1.4 – column buckling curve “b” – can adequately predict the ultimate column strength. Comparisons between numerical failure load and predicted Eurocode buckling ultimate torsional load showed excessive conservatism. Given this, modifications were proposed in European code following the same methodology, i.e., changing the column buckling curve.