Experimental and numerical assessments of hot-rolled carbon steel fixed-ended angles in compression. (December 2020)

• Record Type: Journal Article
• Authors: da S. Sirqueira, A.; de Lima, L.R.O.; da S. Vellasco, P.C.G.; Sarquis, F.R.; da Silva, A.T.
• Is Part Of: Thin-walled structures. Volume 157(2020)
• Publication Date: 2020-12
• Subjects: Carbon steel -- Equal-leg angles -- Columns -- Flexural-torsional buckling -- Experimental analysis -- Numerical study -- Design codes; Thin-walled structures -- Periodicals; 690.1
• DOI: 10.1016/j.tws.2020.107018
• Languages: English
• ISSNs: 0263-8231

Abstract

Abstract: Towers, trusses and bracings diaphragms generally utilise angles cross-sections. Although the angles represent one of the simplest steel cross-sections, their design and structural response are usually not simple. This paper addresses the behaviour of carbon steel hot-rolled equal-leg angle cross-section under compression subjected to the flexural-torsional buckling failure mode. The adopted methodology encompassed an experimental campaign consisting of eighteen full-scale tests on ASTM A36 carbon steel equal-leg angle columns. Three different cross-sections were utilised, L64x64x4.8, L76x76x6.4 and L102x102x6.4 corresponding to b/t (leg width to thickness) ratios of 13.33, 11.88 and 15.94, respectively. All investigated columns presented flexural-torsional buckling failure modes characterised by major axis bending accompanied by a cross-section rotation. This experimental programme was followed by finite element simulations, validated against the experimental results, taking into account the geometrical and material nonlinearities. These models were used to expand the database involving the flexural-torsional buckling response in fixed-ends hot-rolled angle columns made of carbon steel. Afterwards, the results were compared with Eurocode 3 (EC3) and modified DSM (mDSM) predictions. The EC3 presented more significant discrepancies when compared to experiments and numerical results, confirming the conservatism of this code. On the other hand, the performance of the mDSM method was significantly better. Highlights: 1. An experimental programme hot-rolled carbon steel ASTM A-36 equal leg angle under flexural torsional buckling was carried out; 2. A numerical model based on FEM was validated against experimental results and used to enlarge the database of the studied structural elements; 3. The Eurocode 3 (EC3) and Modified Direct Strength Method (mDSM) were used to access the columns resistances; 4. The mDSM predicted very well the columns' resistances.