Axial capacity of perforated steel columns

A research group has recently been formed at the University of Salford with the general aim of investigating lightweight structures. The first task of the group is to look at the behaviour of perforated steel columns used for storage racking. The steel columns used in storage racking are made from perforated light gauge steel, with the perforations facilitating the connection of the storage racking beams. Recent work by Casafont et al. [1] has investigated the axial capacity of such members by a combination of testing and calculation, whereas another approach has been reported by Dinis et al. [2]. This paper describes the initial work of the group, investigating the possibility of assessing such capacity by using Eurocode 3 [3] equations to calculate the failure load of the column, using a critical buckling load that allows for the perforations in the column [4]. Critical buckling loads are calculated using both generalized beam theory and finite element analysis. The use of generalized beam theory is illustrated for problems of varying complexity, from a very simple uncoupled solution with one equation up to the final coupled finite difference eigenvalue solution. The paper concludes that it is currently possible to predict the capacity within a 15 % margin, and that further work could indeed improve this.