Study on shear mechanism and design method of three-edges-connected composite plate shear wall partially infilling in steel frame

Composite plate shear walls-concrete encased (C-PSW/CE) are effective for the lateral-load resisting with their high lateral stiffness and energy dissipation capabilities. C-PSW/CEs are typically connected on all edges to the boundary frame, generating the fully infill shear walls. However, they not only hinder the spatial flexibility of buildings but also impose significant requirements on the boundary frame. This paper proposed three-edges-connected C-PSW/CEs. They were partially infilled in the steel frames (CPSW-PF-SFs), leaving openings and unconnected beam parts in the middle. Link parts accordingly formed. Obviously, the links improved the lateral-load resistance and the opening gave more spatial switching of building. To date the researches on CPSW-PF combining with links in the boundary frame for carrying the seismic loads were limit. Thus, the mechanics characteristics and the interactions of the CPSW-PF-SF were studied by the test and finite element analyses. The results indicated that under cyclic loading, the CPSW-PF-SF exhibited a reasonable lateral-load resisting mechanism. CPSW-PFs served as the primary lateral load-resisting components, and promoted the plastic deformation of the link parts in boundary beams. The boundary columns significantly contributed to the ductility of structure. Based on these shear mechanism, the formulas for the shear stiffness and strength of CPSW-PF-SF were proposed.