Seismic analysis on mid-rise cold-formed steel structure with reinforced end studs

Mid-rise cold-formed steel (CFS) structure with reinforced end studs can promote the development of mid-rise CFS residential buildings from low-rise ones. To analyze the dynamic characteristics of mid-rise CFS residential structures with reinforced end studs under earthquakes, a simplified calculation model of CFS shear wall with reinforced end studs, which is the main lateral load-bearing structural component of the structure, was proposed. The proposed model could consider the real behavior of beam-column joint, and then the seismic calculation model of the whole structure was further obtained. Lateral design objectives for the structure under earthquake were proposed according to abroad specification and previous shear wall test results that performed by authors, and seismic analysis on a mid-rise CFS structure with reinforced end studs was carried out. The results show that equivalent-bracing model considering the mechanical behavior of beam-column joint can precisely predict the seismic performance of the structure. It is safe and reliable that 1/300 and 1/75 being taken as the elastic and inelastic storey drift limits of the structure under frequent and severe earthquake, respectively. Mid-rise CFS structure with reinforced end studs will not collapse under severe earthquake with a degree of 9. It is not suitable to adopt shear wall combination with large difference in stiffness between two directions, and the shear strength of the walls along the direction with larger opening rate should be strengthened emphatically. In areas of particularly high seismicity, both shear strength of the wall and vertical bearing capacity of end studs should be taken into account to avoid overall failure, which is caused by end studs' buckling. © 2017, Editorial Board of Journal of Harbin Institute of Technology. All right reserved.