Axial compressive behaviour of cold-formed steel single-stud wall panels with one-sided sheathing and two-sided dissimilar sheathing board configurations: Experimental and analytical study

Abstract

For practical reasons, it is typical for different types of sheathings (referred to as dissimilar) to be connected at both flanges of the stud (lipped channel-section) in cold-formed steel (CFS) panelized construction (e.g. one side has interior sheathing and the other exterior sheathing). However, limited studies are available on the axial behaviour of CFS studs with different combinations of sheathings present at both-flanges of a stud. This novel experimental study investigates the structural behaviour of nineteen (19) CFS panels with sheathing on one side only and different sheathing on both flanges of the wall panel using combinations of eight (8) different sheathing board types [fibre-cement boards (FCB) (8 mm/10 mm/12 mm thick); calcium silicate boards (12 mm thick); orient strand board (12.5 mm thick); and heavy duty FCB (6 mm/9 mm/12 mm thick)]. Also, first time an attempt is made to study the effect of dissimilar configuration using eight (8) different sheathing board types on axial strength of CFS panels in India. Experimentally tested single stud wall panel specimens consist of; one bare single-stud; eight (8) specimens sheathed with different types of sheathing boards on one flange only; and ten (10) specimens with combinations of different sheathing boards on both-flanges. Average test results are obtained by performing two (02) tests for each specimen. The strength enhancement of a bare single-stud from the sheathing boards has been investigated by testing specimens with a single layer of sheathing at one-flange and combinations of different sheathing boards on both-flanges. The ultimate axial compressive strength, load–deformation behaviour and failure patterns are the parameters compared. A new analytical and semi-analytical design methodologies namely; Rayleigh–Ritz (R-R) method and finite-strip method based on direct strength method (DSM) are adopted for evaluating the axial compressive strength of the CFS wall panels with dissimilar sheathing. Limited studies are available to verify the efficacy of R-R method and DSM to estimate the axial compressive strength of CFS wall panels with dissimilar sheathing on both flanges. Results establish that DSM may be used efficiently rather than the R-R method for axial compressive strength prediction of dissimilar sheathed CFS wall panels. The predicted values show good agreement with the experimental test results, and therefore, demonstrate that the semi-analytical method may be applied efficiently in design.