Behaviour and performance of OSB-sheathed cold-formed steel stud wall panels under combined vertical and seismic loading

This paper investigates the in-plane lateral behaviour and capacity of cold-formed steel (CFS) stud wall panels which are sheathed with Oriented Strand Board (OSB). Detailed nonlinear FE models of the panels were developed, accounting for nonlinear material properties, geometric nonlinearity, realistic fastener behaviour and geometric imperfections. The models were validated against available experimental data and subsequently employed to conduct comprehensive parametric studies into the effects of key design variables, including the screw spacing, the OSB and CFS element thicknesses, the board layout configuration, the intensity of the gravity loading and the number of boards (single- vs. double-sheathed systems). The structural performance of the studied panels was compared in terms of their lateral load capacity, initial stiffness, failure mechanisms, deformation capacity, ductility, and energy dissipation. Lateral capacity, initial stiffness and energy dissipation were positively influenced by a reduced screw spacing, thicker OSB and an absence of seams in the boards. Ductility and deformation capacity were generally promoted by increased screw spacing, thinner OSB and vertical seams. High vertical load ratios have the potential to dramatically reduce lateral strength, ductility and energy dissipation.