Investigation on the Design Method of Shear Strength and Lateral Stiffness of the Cold-Formed Steel Shear Wall

The assembled cold-formed steel stud shear walls are the main lateral force resisting members of cold-formed steel residential buildings. In this paper, three cold-formed steel shear walls with different types of sheathings (gypsum board and OSB board) were tested under the monotonic lateral loading. The failure modes, the shear strength, and the load-displacement curves of the shear walls were obtained and analyzed to investigate the relationship between screws and shear walls. The test results showed that the material types of the sheathings influence the shear strength of the CFS shear wall greatly. The sum of shear strengths of CFS shear walls with one-side gypsum board and CFS shear walls with one-side OSB board is close to that of the CFS shear wall with the both-sided board (one side is gypsum board and the other side is OSB board). The shear strength of the screws between the board and the CFS stud plays a decisive role in the shear strength of the CFS shear wall, which is usually governed by the shear strength of the screw connections. The design methods of the shear strength and the lateral stiffness of the CFS shear walls were proposed and evaluated by comparing the calculated results with the test results. The comparison results demonstrated that the modified design method of shear strength is conservative and feasible to predict the shear strength of the CFS shear wall. The design method of the lateral stiffness of the CFS shear wall is available to calculate the lateral displacement of the CFS shear wall under the elastic stage, but it is not useful under the nonelastic stage. The proposed design methods can be served as a reference for engineering practice.