Contribution of OSB Sheathing to Racking Capacity of Cold-Formed Steel Frames

In recent years, new innovative systems to ensure high structural and environmental performance have emerged in constructional steel practice. Among others, modular construction using cold-formed steel (CFS) frames which offer some advantages over conventional structural system counterparts, such as high strength-to-weight ratio, controlled material quality and sustainability. Wood-sheathed shear wall is one of the lateral load resisting systems adopted in CFS modular construction. It is composed of CFS C-shaped framing members (chord studs, studs and tracks) attached to wood sheathing using fasteners. The resistance capacity of these shear walls, when subjected to in-plan lateral loads, is governed by the connections between the frame and the sheathing board. It is therefore crucial to quantify the shear capacity of sheathing-to-frame fasteners. In this context, a testing rig was developed consisting of two CFS lipped channels facing back-to-back connected on the flanges by oriented strand board (OSB) and loaded such that the 8 connecting fasteners experience shear. The prevailing role of sheathing thickness and fastener type is highlighted in the results. The experimental results are summarized for further use in the analysis of shear walls under lateral load.