STUDY ON THE SEISMIC PERFORMANCE OF COLD-FORMED STEEL FRAME WITH SHEAR ENERGY DISSIPATION K-SHAPED BRACES

To improve the seismic behavior of cold-formed steel (CFS) structures and promote the development of multi-storey CFS structures, a CFS frame with shear energy dissipation k-shaped braces was proposed in this paper. The quasi-static tests of two full-scale one-storey one-bay specimens were carried out. By changing the width-to-thickness ratios of energy dissipation panels, the seismic performance indexes of the specimens were obtained and evaluated. In addition, to investigate the influence of diaphragm effect, the above two specimens were covered with 12 mm-thick gypsum boards on both sides in ABAQUS, and the seismic performance of the structures were studied. Furthermore, the models for multi-storey CFS frames with shear energy dissipation k-shaped braces were established and the elastoplastic dynamic time history analysis was carried out. The test and finite element analysis results showed that the structures proposed had plump hysteretic curves. Before the 2% inter-storey drift, the damage was mainly concentrated on the energy dissipation plates, and energy was dissipated by the plates too. The ultimate load carrying capacities and lateral stiffness of the structures were increased after the double-sided cladding of the gypsum boards, but it did not affect the failure modes of the structures. Compared with the CFS plate shear wall structure, the inter-storey drift of the structure proposed was significantly reduced under earthquakes, and the reductions of the horizontal and longitudinal inter-storey drift were 43.29% and 46.25% respectively under an 8 degree rare earthquake.