EUROSTEEL 2017, September 13–15, 2017, Copenhagen, Denmark Behaviour of gypsum sheathed cold-formed steel stud walls under lateral loadings Sivaganesh Selvaraj a and Mahendrakumar Madhavan* ,a a, * ,a Dept. of Civil Engineering, IIT Hyderabad, India a ce13p1009@iith.ac.in, * ,a mkm@iith.ac.in, ABSTRACT Gypsum board is a common sheathing material for a steel wall panel systems being used with cold- formed steel (CFS) studs. However, the effect of sheathing material to the panel system is under study by many researchers. Therefore, an experimental investigation was carried out to investigate the behaviour of CFS wall studs studs under flexural loading. A total of 24 full scale single stud panels were tested on unsheathed and both side sheathed panels. The parameters studied were C channel dimensions, sheathing thickness and fastener spacing. The experimental results were compared with the design specifications of AISI and found to be conservative. 1 INTRODUCTION The CFS wall panels are usually made of CFS frames sheathed with material of choice such as Gypsum boards, OSB boards, CFS sheets as shown in Fig. 1. The studies by many researchers in the past [1-10] indicate that the sheathing effect changes the buckling mode and influence the strength of the CFS member. However, the available standard specification of AISI S100 -12 [11] does not takes the effect of sheathing into account and recommends the all steel design which ignores the contribution due to sheathing. In addition, recent studies [10] indicate that further improvements in the current AISI S100-12 [11] is required mainly on the interaction buckling failure modes. Fig. 1 Typical CFS-wall panel with sheathings Prior investigations were mainly focused on axial compression of CFS wall panels lined with various sheathings. The study parameters were sheathing type, sheathing thickness, symmetrical or unsymmetrical sheathing on either side of the panel and fastener spacing. Studies on CFS wall panels under lateral (out of plane) or flexural loading however is minimal as per authors knowledge especially after the study carried out Winter’s group in 1972 [1]. Therefore, the present investigation is aimed to study the effect of sheathing using gypsum boards under the major axis four point bending test on CFS unlipped C channels. wileyonlinelibrary.com/journal/cepa © Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin · ce/papers 1 (2017), No. 2 & 3 1707 https://doi.org/10.1002/cepa.214