Experimental and numerical study on seismic performance of a novel type of cold-formed steel shear wall with built-in sandwich panels

The purpose of this paper is to study the seismic behavior of the cold-formed thin-walled steel composite wall with built-in honeycomb sandwich and analyze its failure mechanism. A total of 13 monotonic and cyclic loading tests of wall specimens were completed in this paper, including four for observing the force and failure mode of the built-in sandwich of cold-formed steel (CFS) frame specimens, and nine specimens sheathed with double-sided oriented strand board (OSB). The mechanical performance indicators such as shear bearing capacity, stiffness, ductility, energy dissipation capacity and stiffness degradation of the honeycomb sandwich and other sandwich CFS shear walls were compared and analyzed. The experimental results demonstrate that the failure mode of the wall specimens is mainly ductile failure, including chord stud buckling or tearing, screw tilted, sank into the panel, or cut off at the connection between the honeycomb sandwich and the track. The built-in honeycomb sandwich can play a better role as a skin, which can significantly improve the shear bearing capacity and stiffness of the composite wall, but reduce the ductility. The sheathing and studs can effectively limit the out-of-plane buckling deformation of the sandwich panel and give full play to the properties of the sandwich material, thereby improving the shear bearing capacity, stiffness and energy dissipation capacity of the wall, as well as improving the ductility. The effects of wall aspect ratio and sandwich thickness on the seismic behavior for the built-in honeycomb sandwich CFS shear wall were analyzed by finite element analysis (FEA) and compared with the flat steel plate sandwich and OSB plate sandwich wall. And the nonlinear simplified analysis model of the composite wall under cyclic loading was established by SAP2000.