Finite Element Analysis On Seismic Behavior Of Concrete Filled Steel Tube-concrete Ring Beam Joints

Recently with the increasing attention paid on the concrete-filled steel tube structure,it has been widely used in engineering. The concrete filled columns to beam joints withpenetration components as a new form of the joint has great theoretical and practical valuefor the study the mechanical performance and design method of the joints in engineering.In order to ensure the safety and reliability of the whole structures, detailed analysis onmechanical behaviors of concrete-filled steel tube structure is carried out. It will providean important reference for the design and engineering applications of joints.According to the project practice, a finite element model for the concrete filledcolumns to beam joints with penetration components is made with the nonlinear finiteelement analysis software ABAQUS in this thesis. With the help of numerical simulation,this thesis studies not only the ultimate bearing capacity of the joint with the monotonicloading imposed on the joints, but also the stress mechanism, failure characteristics,deformation ability and the characteristics of hysteretic curve of the joints with the cyclicloading imposed on the inclined column and vertical column.The results suggest that:(1) When the tilt angle of column is small, it has little effecton the mechanical properties of joints. Similar to the seismic performance of tilt columnand vertical column;(2) The collapse of joint starts from the crack in the connecting pointof frame beams and ring beams, but the maximum stress is located at the cross section ofsteel tube. The non-yield of the shear ring in the collapse of the structure shows that shearbearing capacity of reinforcement ring and the friction of steel tube and ring beam canwithstand the shear force between concrete filled steel tube and reinforced concrete ringbeam;(3) Under the monotonic loading, the position of nodes has little impact on thebearing capacity, and the yield load of symmetrical beam and oblique beam is similar;(4)And under the cyclic loading, the hysteretic curve simulated by finite elements is quite full;ductility factor and viscous damping coefficient conform to the seismic norms.