Experimental behaviour of steel reduced beam section to concrete-filled circular hollow section column connections

In this paper, five specimens of connections of reduced beam section (RBS) steel beam to concrete-filled steel tubular (CFST) circular hollow section (CHS) column using an external ring were tested. The experiments considered the hysteretic behaviour under combined constant axial load and cyclic lateral load. For comparison, three specimens of a weak-column without an RBS configuration steel beam to CFST column connection were tested under the same conditions. The axial load level of the CFST column, width of connection stiffening ring and RBS configuration were considered as the experimental parameters of their seismic behaviour. It was found that the lateral load (P)(P) versus lateral deformation (Δ)(Δ) hysteresis curves exhibited no obvious strength deterioration and stiffness degradation. The energy dissipation of the RBS connections is significantly improved when compared with weak-column connections. The concrete filled CHS columns failed as a weak-column connection and their energy dissipation capacity was reduced. It can be concluded that the RBS connections exhibit good seismic performance.