A commentary on torsion in steel open sections

Abstract

This article raises awareness on the fact that torsion in steel open sections is a complex phenomenon, especially when combined with other actions, and accurate predictions of the structural response are hard to make. The goal is to show, through a couple of practical examples, that aiming to utilisations close to 100% may not be always the most sensible decision if some aspects of the design are not fully defined. The first example shows how a shortcut frequently taken is not necessarily a safe design path, the second focuses on how a broadly-known case study from the literature is indeed behaving differently and is closer to failure than originally intended.