Seismic performance of self-centering circular concrete-filled steel tubular column to steel beam connection with web friction device

Abstract

A novel self-centering circular concrete-filled steel tubular (CFST) column to steel beam connection is developed. The connection has a beam web friction device (WFD) that provides energy dissipation and post-tensioned (PT) high-strength steel strands running parallel to the beam. The PT strands provide self-centering behavior to the connection. The mechanical behavior of the connection was analyzed theoretically. Three full-scale specimens were tested to investigate the mechanical characteristics of the connections under low-cyclic reversed loading. And the effects of the parameters including the initial posttensioning force, the pretension force in the friction bolts though WFD and the number of PT strands on the performance of the connection were examined experimentally and numerically. Both the experiment and simulation results show that the self-centering capacity increased with the increase of initial PT force or the number of PT strands, however, decreased with an increase in the pretension force in the friction bolts; while the energy dissipation increased with an increase in the pretension force in the friction bolts. The beam and column remained elastic under 5% inter-story drift; the PT strands and WFD can provide excellent self-centering and reasonable energy dissipating capacities for the connection, respectively.