STUDY ON THE MECHANICAL PROPERTIES OF COLD-FORMED STEEL FRAMED SHEAR WALL WITH SLITS

In order to study the mechanical behavior of the cold-formed steel framed shear wall with slits (CFS-WS) which is suitable for low-rise and multi-story cold-formed thin-walled steel buildings, pseudo-static tests of 1 ordinary CFS-WS and 3 buckling-restrained CFS-WS were conducted to gain the mechanical properties of CFS-WS, including the failure modes, load-displacement hysteresis curves, skeleton curves and energy dissipation capacities, and the design value of shear capacity was put forward. The test results indicates that the CFS-WS relies on the "torsion-recovery-reverse torsion" of steel plate between vertical slits and the deformation of the steel frame to resist horizontal loads and dissipate energy. The steel plate tears and the end of the hat column buckles when the CFS-WS is broken. The CFS-WS has good bearing capacity, plasticity, ductility and energy dissipation capacity; however, the rheostriction of its load-displacement hysteresis curve is rather severe. Compared with ordinary CFS-WS, the buckling-restrained CFS-WS has higher shear stiffness, bearing capacity and energy dissipation capacity, and the rheostriction of its load-displacement hysteresis curve is mitigated. Furthermore, the stiffeners and the cold-formed steel beams and columns are connected to form a steel frame through the stiffener connectors, which can effectively enhance the early shear stiffness, bearing capacity and energy dissipation capacity of CFS-WS, and greatly improve the seismic performance of the structure.