Experimental Research on Seismic Behavior of Concrete Filled Steel Tubular Column Ring Beam Joint Under Cyclic Loading

Concrete ring beam joint is a new type of connection for joining the concrete filled steel tubular column and the concrete frame beam. By experiment on fourteen concrete filled steel tubular column ring beam joint specimens subjected to cyclic lateral load, the seismic behavior of the ring beam joint was studied with the following achievements obtained. No matter the plastic hinge was at the end of frame beam or on the ring beam the specimens had large elastic plastic deformation capacity. The rotation angle of the column ( i.e.the relative story drift) was larger than 1/120 for most specimens when the maximum load was reached and the hysteresis loops were plump. At the descending stage of lateral load the loops had differing extent of pinch. In general the specimens exhibited good energy dissipation capacity. Due to the independence of the concrete filled steel tubular column and the ring beam at the connection, failure of the joint would not influence the load carrying capacity of column.