Cyclic performance of steel frame fabricated with cold-formed steel composite wall structure

Abstract

In this study, a novel hybrid wall structure of a hot-rolled steel frame fabricated with a cold-formed steel (CFS) composite wall is proposed. Ceramsite concrete is lightweight concrete that is used in CFS composite walls. The seismic performances, including the failure mode, hysteretic behavior, shear capacity, stiffness, ductility, and energy dissipation performance, of four specimens of steel frame fabricated with CFS composite wall and one specimen of conventional CFS composite wall were evaluated under low-cyclic loading. The experimental results showed that the collaborative working performance of the steel frame and infilled CFS composite wall was optimum, and the proposed fabricated wall structure had a significant effect on the bearing capacity, stiffness, and energy dissipation capacity. The infilled CFS composite walls were damaged earlier than the steel frames. The damage was primarily characterized by the compressive failure at the corners of fillers, loss of diaphragm effect, screw connection failure, and bond-slip failure between the CFS framing and fillers. However, the steel frames exhibited no obvious damage, which effectively restrained the infilled CFS composite walls and prevented them from severe collapse. In addition, enhancing the strength of the fillers and increasing the section area of the studs improved the bearing capacity of the structure; however, they were detrimental to the ductility. Wall opening reduced the bearing capacity and initial stiffness of the structure; however, it improved the ductility. Furthermore, a superposition method was used to calculate the bearing capacity of the proposed structure. The calculated results showed a superior accuracy in comparison with the experimental results.