Investigations on cold-formed steel wall panels with different sheathing boards under axial loading: Experimental and analytical/semi-analytical studies

Abstract

Sheathed cold-formed steel (CFS) wall panels consists of studs, tracks and sheathings. Sheathing is attached to the CFS frame using self-drilling screws which influences the strength of wall panels under axial loading. As observed in literature, sheathing affects the strength and failure mechanisms of CFS wall panels. Most of the previous studies are conducted using gypsum and orient strand boards (OSB). Limited studies are available on behaviour of CFS stud with fibre cement board (FCB), heavy duty fibre cement board (HDFCB), calcium silicate board (CSB) and magnesium oxide (MGO) board sheathings. For the first time, a comparative experimental study is presented on axial performance of CFS wall panels using FCB, HDFCB, CSB, OSB and MGO boards. Axial strength, load-deformation response and failure modes are studied and estimated. Load factors (Wn/WSingle-Stud) are also evaluated for all specimens, which may be adopted by designers and researchers in absence of experimental data. Different analytical and semi-analytical design methodologies are adopted for evaluating the strengths of CFS wall panels namely; Differential Equation of Equilibrium based method, Rayleigh-Ritz method and Direct strength method (DSM) as per AISI S100. Limited studies are available on comparing the efficacies of available design methodologies. The present study also investigates the efficacy of such analytical/semi-analytical tools for evaluation of axial strength of CFS panels with sheathing. For the first time, a problem is undertaken to compare all the three (03) mathematical models. Results demonstrate that DSM may be used effectively for axial strength prediction of sheathed CFS wall panels. Further, DSM is used for predicting the axial strength of the tested specimens. The predicted results agree well with the experimental results.