An Experimental Study of Seismic Performance of Cold-formed Thin-walled Steel Shear Walls Using Delay Protection Bracing

This paper presents a brace with function of delay protection and its working mechanism to solve the problem that cold-formed steel (CFS) shear walls with corrugated steel sheathing have low ductility and bad deformation capability. Three CFS shear walls using delay protection bracing and one regular CFS shear wall were designed by considering the effect of different sliding distances of the brace. An experimental study of seismic performance on these shear walls was conducted. The failure modes and the failure mechanism of shear walls were indicated, the influence of different sliding distances of the brace to the seismic performance of CFS shear walls was analyzed, and the working principle of the brace was verified. The test results show that the failure modes of the CFS shear wall using delay protection bracing are the buckling of the corrugated steel sheets, the failure of the screw connection between panel and boundary stud and the yield of the steel tensile strip installed in the brace. The sliding distance of the brace has an optimal value. The ductility, ultimate deformation capacity and energy dissipation of CFS shear walls can be improved by installing the brace of delay protection with optimal sliding distance. It can also decrease the speed of stiffness degradation and make the shear walls keep high strength and lateral stiffness.