An Experimental Study of Seismic Performance of Cold-formed Thin-walled Steel Composite Walls With Different Hybrid Connections

To solve the problem of low seismic performance of cold-formed steel (CFS) composite walls with self-piercing riveted connection, five full-scale test specimens were tested under cyclic loads, including one CFS composite wall with self-piercing riveted connection, two CFS composite walls with hybrid connection in replacing rivets with screws locally(including continuous replacement and interval replacement), two CFS composite walls with hybrid connection in adding screw locally(including continuous adding and interval adding). Factors that influence the seismic behavior of CFS composite walls including four different ways of hybrid connection were studied, the bearing capacity, ductility, energy dissipation and failure mechanism were obtained, and a hybrid connection method with better seismic performance was proposed. Experimental results show that the main failure modes of CFS composite walls include sheet buckling, pull-over of sheet from rivet head and pull-over of sheet from screw head; the seismic performance of the CFS composite walls are not improved obviously by replacing the rivet with the screw. The shear resistance, stiffness, ultimate displacement and cumulative energy dissipation of the CFS composite walls can be significantly improved by adding screws locally, especially, the yield displacement of the CFS composite wall can be significantly improved by continuously adding screws locally. It is advisable to give priority to the way of hybrid connection with the locally continuous increasing screws in the design and application of CFS composite walls.