On the buckling and post-buckling behavior of thin-walled pre-twisted columns

Abstract

A beam finite element for pre-twisted beams is presented and employed to assess the linear, buckling and post-buckling behavior of uniformly compressed members (columns) with thin-walled rectangular section. The element follows the so-called “geometrically exact” concept and can be viewed as an extension/specialization, to the pre-twisted case, of that previously developed by the authors (Peres et al. 2021). Torsion-related warping and arbitrary mid-line warping/extension effects are included. As shown in the examples presented in the paper, the element is capable of capturing the twist-extension coupling that occurs even in the linear case. In fact, the element provides very accurate linear, buckling and post-buckling solutions for pretwisted columns.