Experimental study of blind bolted joints to concrete-filled thin-walled steel tubular columns under cyclic loading

This paper discusses results of experiments on blind bolted end plate joints to concrete-filled thin-walled steel tubular (CFTST) columns. Four exterior joints to CFTST columns subjected to cyclic loadings. A feature of this novel joint is the use of the blind bolts and extensions to these bolts into the concrete-filled square steel tubular column. Failure modes, moment-rotation hysteretic curves and energy consumption of the connections were analyzed. Further, the connection rigidity and ductility were also elevated by present specifications. The test results showed that the end plate type and the steel tube thickness affect the seismic behaviour of the typed blind bolted end plate joints. The proposed joint has reasonable strength, stiffness and ductility by taking reasonable end plate type, steel tube thickness and blind bolt anchorage; its ultimate connection rotation satisfies the ductility design requirements, and could be reliably and safety used in low-layer or multi-layer composite frames