Research On Cyclic Behavior Of Composite Joints Between Circular Hollow STRC Columns And H-shaped Steel Beam

With the application of steel tube-reinforced concrete(STRC)column in high-rise buildings,hollow concrete filled steel tube composite column is derived from the concrete filled steel tube composite column.This is a new combination structure,In recent years,the research on its mechanical properties is becoming more and more perfect.The research on the hollow STRC column and H-shaped steel beam joint is still rare,and the detailed mechanism analysis is lacking.In this paper,the seismic behavior of hollow STRC column and H-shaped steel beam joint is studied by the research combination of experimental and theoretical,the specific works are as below:1.The seismic load tests of four connections between hollow STRC columns and H-shaped steel beam were carried out with the main parameters of the axial compression ratio、the thickness of the sleeve and beam height.The constant axial load applied on the top of column and reserve cyclic loading at the end of the beams.The influence of the above parameters on the bearing capacity and failure pattern,the strength degradation,stiffness degradation,ductility and energy dissipation capacity of the joint specimens under cyclic loading were analyzed.The results showed that the load versus deflection curve were plump under cyclic loading,the failure modes are the bending failure of the beam ends.Therefore,this type of joints has a good seismic performance.2.Finite element analysis(FEA)software ABAQUS was conducted numerical modeling.The FEA model considered plastic damage degradation effect of concrete、selection of cells,reasonable meshing method,interface contact processing.The test date was used to verify the applicability of this FEA model.3.The working mechanism of the composite joint was analyzed by the test results and FEA model,understanding the failure rule of this kind of joint.The bearing capacities and failure mode are affected by the axial load ratio of column,the ratio between the bending capacities of the beam and column,the beam to column stiffness ratio;The parameters such as the concrete strength of the composite column and the strength and thickness of the inner steel tube have little effect on the seismic performance of the joint.