Seismic Performance Study On The Composite Joint Of Concrete-filled Steel Tubular-RC Beam

Taking two types of joint of concrete-filled steel tubular-prestressed concretebeam used in an underground structure project as object, quasi-static test andsimulation methods were carried out to study the seismic performance of the joint.The ductility, rigidity, bearing capacity and energy dissipation capacity werecomprehensively evaluated based on the test results and finite element analysis. Themain achievements can be summarized as follows:(1)4model specimens of CFST composite joints are designed and manufactured,and divided into two groups in accordance with the form.The bearing capacity andstiffness of specimens are checked according to the two China’s current design codes.(2)Quasi-static test was carried out to evaluate the seismic performance of thejoint. The ductility bearing capacity, rigidity and energy dissipation capacity werestudied based on the text results.(3)Applied ABAQUS software, the finite element models of the2groups ofspecimens are established respectively. Nonlinear analysis was performed on CFSTcomposite joints. To verify the rationalty of the modle, numerical analysis results werecompared with the text results.The experimental results indicate that the seismic performance of the joint isgood. High ductility, bearing capacity and energy dissipation capacity are observed.Considering the displacement demand in the severe seismic event, the deformation ofjoint core area is small, and damage is not developed. The requirements of the designare met. Using the finite element analysis to simulate the hysteretic behavior of thespecimens, compare with the text results, the force-displacement curve obtained fromfinite element analysis agrees well with the text results. The modeling approach of thejoint is correct.