Experimental and numerical investigation on full-scale tension-only concentrically braced steel beam-through frames

This paper presents an experimental investigation on two full-scale tension-only concentrically braced beam-through frames (TOCBBTFs) with through beam bolted connections. This type of TOCBBTF system features cold-formed square-tube section columns connected to H-section through beams by bolted end plate. It is commonly used in low-rise prefabricated buildings. Two two-story, four-span by one-span TOCBBTFs subjected to design vertical load were cyclically loaded horizontally to examine the seismic behavior. Stable behavior was observed up to a story drift angle of 1/10. The cyclic behavior was characterized by a linear response, followed by a slip range and a significant hardening response. Deteriorating pinched hysteresis was observed due to the occurrence of cyclic brace compression buckling and tension yielding. The structural damage evolution, ductility, stiffness and shear force distribution of the TOCBBTFs were investigated. Moreover, the finite element software ABAQUS was used to investigate the behavior of TOCBBTF by nonlinear analysis. Semi-rigid analysis produced the most reasonable prediction including initial lateral stiffness and peak story shear. The calibrated numerical models can be employed to launch further studies for this structural system.