Research On Shear Capacity Of RC Beam-CFST Column Joint Connected With Ring Beam

It has nearly a century of history from the earliest applying of concrete filled steel tube. Due to the high load capacity, good ductility and toughness, convenience of production and construction, good fire resistance, good economic benefits of concrete filled steel tube, and accompanied by the vigorous development of China, in high-rise buildings, bridges, metallurgy, shipbuilding, electric power industry steel concrete structure has made significant economic benefits and application increasingly widespread in the past20years.Concrete filled steel tube beam-column joint play a very important role in structural safety. RC beam-CFST column Joint is welded steel on the outer surface of CFST as shear ring and pouring concrete ring beam around it. Passing moment by concrete ring beam surrounded the steel tube and passing shear by shear ring and the static friction arising from the distortion of ring beam between concrete and steel tube.Since the ring beam joint has been proposed, many static and low cyclic experiments have been made. But the number of research on shear capacity of RC beam-CFST column joint Connected with Ring Beam is quite few. Based on theoretical calculations, by using ABAQUS finite element analysis software for nonlinear finite element analysis of the ring beam joint, while comparing with ZJ-1joint discuss the affection of the number of shear ring, the strength grade of concrete, reinforcement ratio, ring beam section and diameter of the CFST column to the mechanical behavior of the ring beam under monotonic load. The result show that the RC beam-CFST column Joint has high bearing capacity and small slip under direct shear; The shear ring has no negative impact on the bearing capacity of CFST column; Increasing the strength grade of concrete, reinforcement ratio can improve the bearing capacity obviously; The ring beam joint is best used for the large diameter of CFST column, when diameter of CFST column is not large, we suggest the ring corbels as joint; Shear ring should set two, one is on the middle of ring beam, the other is on the bottom of ring beam.