Seismic Response Investigation and Analyses of End Plate Moment-Resisting CFST Frames Under Pseudo-Dynamic Loads

This paper reported an innovative semi-rigid composite frame comprised of concrete-filled steel tubular (CFST) columns and H-shaped steel beams assembled using flush or extended end plates with blind fasteners. Two specimens of two-story single-bay end plate moment-resisting square or circular CFST frames were investigated by a series of pseudo-dynamic tests. To analyze dynamic response of this type of structure under the earthquake action, time history response and story drift were investigated. The influence of the column section type and the end plate type on seismic performance of semi-rigid moment-resisting CFST frames under different earthquake loading levels were also discussed according to hysteretic behavior, rigidity degradation and energy dissipation capacity. The experimental and analytical results indicated that at the same section width and steel ratio of the column, the rigidity of end plate moment-resisting square CFST frame was greater than that of circular CFST frame, while the story drift of square CFST frame was smaller than that of circular CFST frame. The type of end plate moment-resisting CFST frames with blind fasteners, which can provide good seismic behavior and energy dissipation ability, can be well used in a seismic region.