Structural performance of cold-formed steel-sheathed shear walls under cyclic loads

Abstract

Non-linear finite element analyses were carried out to evaluate the seismic characteristics of steel-sheathed cold-formed steel (CFS) shear walls using the finite element analysis software ANSYS. The numerical models presented here were verified based on experimental tests considering different structural characteristics including: material non-linearity, geometric imperfection residual stresses, connection non-linearity and perforations. A total of 15 models with various structural characteristics were investigated. Based on the results, it was concluded that the lateral performances of the walls are significantly affected by structural characteristics of the walls including: the thickness of frame members and sheathing plates, edge screw spacing stud spacing and height and span width of the frame. Investigating the research outcomes shows that American Iron and Steel Institute (AISI) standard, considered as the most comprehensive design code amongst the available CFS provisions, only takes into account the wall’s aspect ratio and the fastener spacing in order to prescribe the nominal shear strength of the walls, while the effects of the other structural characteristics are neglected. This brings to a conclusion that the codes and standards, including AISI, should be revised considering various ranges of structural parameters which are being employed in currently-in-use steel-sheathed shear walls in housing industry worldwide.