Seismic damage model for gypsum board-to-CFS stud screw connections considering ground motion duration

•·Shear tests on gypsum board-to-CFS stud screw connections were performed.•·A screw-sheathing abrasion theory was proposed.•·Seismic damage model for gypsum board-to-CFS stud screw connections was established. First, a cyclic loading method of gypsum board-to-cold-formed steel (CFS) stud screw connections was explored, and the impact of ground motion duration was considered. Then, the correlation between the shear behavior of the screw connections and ground motion duration was investigated. Afterward, a screw-sheathing abrasion theory was proposed, and the shear performance degradation mechanism of the screw connections was further revealed. Moreover, a method for determining the load-deformation relationship of the screw connections was established. Ultimately, a seismic damage model for gypsum board-to-CFS stud screw connections considering the impact of ground motion duration was established based on an improvement of the Park-Ang seismic damage model. The results are as follows: (1) The load-deformation curves of the screw connections show nonlinear characteristics accompanied by strength and stiffness degradation and pinching. The primary control of the load-deformation curves and shear damage of the screw connections is extrusion of the screw from the gypsum board. (2) The shear damage of the screw connections is positively correlated with the number of loading cycles originating from long-duration ground motions. (3) A load-deformation relationship of gypsum board-to-CFS stud screw connections considering the influence of the loading path can be established accurately through the proposed screw-sheathing abrasion theory. (4) The proposed seismic damage model reflects the change in the ultimate energy dissipation capacity of gypsum board-to-CFS stud screw connections with a hysteretic energy dissipation process. The damage development of the screw connections can be accurately described, indicating good applicability to sheathing-to-CFS stud screw connections dominated by sheathing bearing failure.