Research On Seismic Behavior And Design Method Of Joints With Perforating Zone Of Circular Tubed Steel Reinforced Concrete(SRC) Column-RC Beam

Tubed steel reinforced concrete structure has high bearing capacity,good ductility,excellent dissipation capacity,and broad development prospects.However,the current research on this structure mainly focuses on the axial compression performance of the column,the research on the connection form and the mechanical performance of its beam-column joints is still lacking.In this paper,based on the test of our research group,the mechanical performance of two types joints with Perforating Zone of Circular Tubed Steel Reinforced Concrete(SRC)Column-RC Beam are studied by using finite element software,and the corresponding seismic design methods and structural measures of the two types joints are put forward.The main contents and results are as follows:(1)Analyzing the test joints to establish the corresponding finite element model and simulate the anti-seismic test.The correctness of the finite element model is verified by comparing the test with the finite element hysteresis curve,skeleton curve and eigenvalues,ductility and energy consumption indicators,strength and stiffness degradation coefficients,and joint failure modes.(2)Selecting the possible parameters affecting the mechanical properties of the joint:concrete strength grade,steel content of section steel,axial compression ratio,diameter-to-thickness ratio and opening ratio of steel tube in joint area,width and thickness of reinforcement ring on steel tube in joint area,beam-column stiffness ratio,variable parameters analysis of RC-1 type joints.Selecting the main parameters affecting the mechanical properties of the joint: axial compression ratio,width of stiffeners and stiffeners on steel pipes in the joint area,beam-column line stiffness ratio,the variable parameters analysis are conducted on RC-2 type joints.Based on the above analysis,and considering the stress condition and economic benefit of the joints,the relevant limit values of the two main types of joints and recommended ranges are proposed: the axial compression ratio of the two types of joints should not exceed 0.3 and do not exceed 0.2,the recommended value range of the width of reinforcing ring is 60mm-120 mm and should not exceed 120 mm,therecommended value range of beam-column stiffness ratio is 1.66-2.21 and should not exceed2.21.The recommended value range for the concrete strength grade of RC-1 joint is C40-C70,and the recommended value range for the steel ratio of section steel is within 0.053.The recommended value range of stiffener width of RC-2 node is recommended to be between60 mm and120mm.(3)Based on the results of variable parameters,and by means of regression and integration methods,the calculation method for the horizontal bearing capacity at the top of the column and the bending and shear capacity of the core area of the joint is proposed.The reliability of the formula is verified by comparing the calculation results with the finite element variable parameter results,which provides a basis for further research.