Behaviour of cold-formed steel framed shear walls with slitted sheathing under lateral loading

Abstract

Cold-formed steel (CFS) framed shear walls (CFS-SWs) with steel sheathing have emerged as promising lateral-force-resisting members in mid-rise buildings of seismic regions. This paper presents a combined experimental and numerical study on a new type of steel sheathed CFS-SWs, whose novel feature is the use of central CFS sheathing with vertical slits. Five full-scale wall specimens were tested under monotonic and cyclic lateral loading to examine the performance of the shear walls. Then a finite element (FE) modelling of CFS-SWs with slitted steel sheathing was established and verified by the experimental data. Further analyses on the parametric effects and the load-carrying mechanism of CFS-SWs with slitted sheathing were conducted. It is found that the slitted sheathing alleviates the premature damage of boundary studs and mitigates the tremors as well as noises during the loading. The wall with slitted sheathing shows good ductility with a 22.84% higher ductility factor than the wall with non-slitted sheathing. The width-to-thickness ratio and the height-to-width ratio of the flexural links between the slits have considerable effects on the stiffness as well as the peak load of the wall. Lastly, the ultimate lateral resistance of CFS-SWs with slitted sheathing was estimated using a simplified method.