Analytical Analysis of Seismic Behavior of Cold-Formed Steel Frames with Strap Brace and Sheathings Plates

Cold-formed steel frames (CFS) are popular all over the world. In this study, we have investigated 112 frames with different bracing arrangements and different dimensional ratios with different thicknesses of sheathing plates under cyclic and monotonic loading using Finite Element Nonlinear Analysis. We also evaluated seismic parameters including resistance reduction factor, ductility, and force reduction factor due to ductility for all specimens. On the other hand, we calculated the seismic response modification factor for these systems. The maximum modification factor among shear wall panels with sheathing plates related to GWB (gypsum wall board) specimen with thickness of 15mm was 5.14; among bracing specimens in bilateral bracing mode related to B sample was 3.14. The maximum amount of resistance among the specimens with bilateral (2-side) bracing systems belongs to the specimen C (2-side double X-bracing) with the dimension ratio of 2 (4.8m x 2.4m) and resistance of 305.60 kN and also among the shear wall panels with sheathing plates, it belongs to DFP (douglas fir plywood) with a thickness of 20mm and resistance of 371.34 kN.