Effect of wall sheathings on seismic behavior of phosphogypsum-filled CFS shear walls

To improve the seismic behavior of cold-formed steel (CFS) walls, a novel infilled CFS wall covered with wall sheathings was presented in this study. Four full-scale specimens were tested under cyclic lateral loads. The wall sheathings, including gypsum wallboards (GWBs), oriented strand boards (OSBs), and fiber cement boards (FCBs), were employed to investigate their impacts on the seismic performance of the walls. The failure process, failure mode, load-displacement curve, strength degradation, stiffness degradation, energy dissipation, deformation, and strain variation of the walls were investigated. Observations of the test showed that the failure modes of the walls are the failure of connections between the CFS frame and sheathing as well as the crushing of the infilled material. Because the peak loads and lateral stiffness of the walls were increased by 1.25-1.72 times compared with the specimen without sheathing, it can be seen that the sheathings play an important role in the lateral resistance of the walls. Additionally, an analysis model and calculation formulas for predicting the lateral stiffness of the walls were proposed. The comparisons between calculated value and experimental data indicated that the proposed theoretical method can accurately predict the lateral stiffness of the wall.