Seismic behavior of bolted beam-to-column connections for concrete filled steel tube

In this paper, a new design of bolted beam-to-column connections for CFT is proposed. A mechanical model is established in order to derive theoretical equations for calculating the stiffness, the yielding shear strength and the ultimate shear strength of the panel zone. Also, a series of cyclic loading experiments have been conducted. The experimental results and theoretical results are very close, which demonstrates that the bolted connections have superior seismic resistance in stiffness, strength, ductility and energy dissipation mechanisms. From the laboratory studies, even though the story angular drift reaches 7% and the plastic angular displacement reaches 5%, the structure still stands. Those results indicate that the seismic resistance exceeds those specified in Taiwan and the US.