Experimental and numerical study of the behaviour of eccentrically loaded cold-formed channel sections – determination of an optimal load eccentricity

Abstract

Cold‐formed channel sections are often used as bracing elements in storage racking structures, with compressive loading representing a common design condition. The introduction of the compressive force is often carried out through bolted connections in the flanges of the section. Whenever the position of these connection bolts is not precisely aligned with the section's centroid, cold‐formed channel sections are loaded in compression and bending. For fabricators of storage racking systems, it is of economic interest to determine the optimum position of these bolts with respect to the maximum design resistance. However, for eccentrically loaded channel sections, the various parts of the Eurocode provide a series of different rules, which lead to conflicting and contradictory statements regarding the optimal position of the compressive load with respect to the centroid. In this paper, the various code regulations are briefly described and compared – for one exemplary channel section without lips and stiffeners – to the results of a series of non‐linear numerical calculations, as well as to laboratory tests designed specifically to study the effect of eccentricities on the cross‐sectional capacity of channel sections.