Experimental Study On Seismic Performance Of Ring Beam Joint With RC Beam And Circular Tubed Steel Reinforced Concrete(SRC) Column

The steel reinforced concrete needs to be fitted with the reinforcement framework to enhance the restraining effect on the concrete.The steel tube of concrete-filled steel tube needs to bear longitudinal load,which causes the steel tube to have the poor restraint effect on core concrete.A new type of load-bearing column which is steel tube confined SRC came into being.At present,the research on steel tube confined SRC focuses on static components.Based on the concrete filled steel tube joints with ring beam and steel tube confined SRC columns,a new type of joint which is ring beam Joint with RC beam and circular tubed SRC column was proposed.The seismic performance of this type of node was evaluated and analyzed,and the key tasks are as follows.(1)According to the relevant building codes and construction specifications,research projects’ group designed and made two full-scale tests of ring beam joint with RC beam and circular tubed SRC column,and the component sizes and detailed design parameters were designed.The main changing parameters of joints are beam height and the reinforcement ratio in the beam.Then,the design of a detailed cyclic loading scheme of test were finished.(2)Seismic performance on joint test RH-1 and RH-2 were studied by loading test,which reflected synthetically seismic performance targets.The results showed that failure mode of joint test RH-1 and RH-2 are beam-end plastic hinge damage.Damage location are away from the joint zone.New joint has higher ultimate bearing capacity,the superior energy dissipation capacity,the superior ability to resist degradation of strength and stiffness,and the good ductility.(3)Combined with the data of stiffness degradation of hysteretic curves and skeleton curves,a hysteretic model of three broken line suitable for ring beam joint with RC beam and circular tubed SRC column was established.Among them,each stage of the skeleton curve model satisfies the linear regression equation,and the stiffness degradation of hysteretic curves satisfies the logarithmic function relationship.(4)Through the simulation-based verification on ring beam joint with RC beam and circular tubed SRC column by simulation analysis software ABAQUS,the results indicated that nonlinear analysis and test results are in good agreement with each other on the failure mode,failure location,load displacement curves and ultimate bearing capacity and so on Finite element model provided with the rationality and accuracy can be used in subsequent research.