Study On The Stability Of Cold-formed Steel Stud Wall Assemblies In Residential Structures

The assembled wall, which is composed of cold-formed steel wall studs, gypsum board and orient strand board(OSB) fixing with screws, is the main vertical bearing structure in the cold-formed steel residential buildings. In this article the stability of the assembled wall is researched, and a design method is offered.Using the pseudo-plate method, the cold-formed steel stud wall assembly is simplified into a mechanical model of orthotropic plate system. Moreover, the formulas to calculate the equivalent stiffness of the orthotropic plate are presented by using the sectional center method, while the influencing factors of the equivalent stiffness are considered. By using the finite element analysis, the simplified model and the formulas have been verified to be valid.Studying from the theory of the plate, the stability of the wall under vertical load is deduced, and the analysis shows that it is mainly related to the depth-thickness ratio of the wall. The method to determine the calculated height of the wall is derived. By analysing the parameters such as the depth of the wall, the spacing of the studs, the materials of the wall boards and the size of the hole, etc, the correction factors of the allowable depth-thickness ratio which is affected by the equivalent elastic modular, whether it is load bearing wall or not, and the hole size of its door and windows is presented. And the corresponding measure to improve the stability of the assembled walls has also been put forward.The design method to assure the stability of the wall by checking the depth-thickness ratio is presented, also a design example is offered, for the reference in practical projects.