A Parametric Study on the Flexural Capacity of Cold-Formed Steel Stacked Built-up Sections

This paper presents an exploratory parametric study on the flexural capacity of an innovative cold-formed steel (CFS) stacked built-up beam section. The built-up section consists of lipped channel sections mounting vertically and screwed together through their lips and webs. Using the Direct Strength Method (DSM), a parametric study of this section is presented. The accuracy of this method is proven by comparing the results of the experiments with the modelling. Different configurations are studied, including sections compromising two, three, four and five channel sections, with thicknesses ranging from 1 to 3 mm. Four different steel grades are considered. The open flange of the built-up sections is covered by a CFS steel sheet cap to make a closed box beam. The effect of different thicknesses of the cap on the flexural capacity is also studied. The impact of the section configuration and thickness is understood to be more pronounced on the flexural capacity.