A FULL-SCALE TEST ON SELF-CENTERING CIRCULAR CONCRETE FILLED STEEL TUBULAR COLUMN TO STEEL BEAM CONNECTIONS

To reduce the residual deformation of concrete-filled steel tubular column-steel beam frame structure after earthquakes, a self-centering circular concrete-filled steel tubular column-to-steel beam connection with web friction devices is proposed. The details of the self-centering connection are introduced and its mechanical behavior was theoretically analyzed. The self-centering and energy dissipation capacities were investigated by quasi-static tests on three connection specimens. The possible failure modes of the self-centering connection and the effect of strand prestress force and bolt prestress force of the web friction device on the mechanical performance of the connection were analyzed. The variation of the strand prestress force and the strain in main parts of the connection were also analyzed. The results show that the connection had good self-centering and energy dissipation capacities. The initial stiffness, the imminent gap-opening moment and the self-centering capacity of the connection increased with the increasing of the initial strand prestress force. The energy dissipation capacity of the connection was enhanced with the increasing of the bolt prestress force of the web friction device.