Effect of Intermediate Stiffeners in an Optimization of Axially Compressed Built‐up Thin‐Walled Column Cross‐Sections According to the Eurocode 3

This paper aims to propose an optimized thin‐walled built‐up cross‐section for axially compressed columns, which can be feasibly produced and utilized in building assemblies. The European standard Eurocode 3 [1] was employed, along with an optimization solving algorithm, to calculate the performance of axially compressed thin‐walled columns. The analysis considered the buckling capacity of the column, encompassing local, distortional, and global buckling modes. 3 types of box cross‐sections were examined: without web stiffeners, with web stiffeners bent inwards, and with web stiffeners bent outwards. The cross‐sections were constructed by connecting 2 “C” type or “Sigma” type profiles through their flanges. In the calculations, the thickness of the overlapping parts of the flanges was assumed to be equal to the thickness of the profiles. Experimental investigations have shown that this assumption, where the overlapping parts of the flanges are considered equal to the profile thickness, is conservative and reliable [2]. Consequently, the built‐up cross‐section can be treated as one rigidly connected entity [3]. The results of the calculations reveal that the optimized built‐up axially compressed column cross‐section with web stiffeners exhibits a higher level of effectiveness, with a cross‐sectional area up to 23% smaller compared to the optimized cross‐sectional area of columns without web stiffeners.