Research On Seismic Behavior Of T-shaped Concrete-filled Steel Tubular Column Joint With The Inner Posted Plate

Designing of concrete-filled steel tubular frame structure is the key problem of seismic design,special-shaped concrete filled steel tubular columns has important advantages in the interior space of the use and aesthetics.Present study on special-shaped steel tube concrete column-steel beam joints is still not perfect,especially on the study of special-shaped concrete-filled steel Tubular column-beam joint.The strengthening node form is proposed on the basis of research on other strengthening node form seismic performance in this paper,established 11 T-shaped tubular concrete column-concrete beam inner posted plate strengthening node model and 9 T-shaped tubular concrete column-steel beams inner posted plate strengthening node model,for researching on node seismic performance by using ABAQUS limited Yuan analysis results.Main contents and conclusions of the analysis are as follows:(1)Analyzing the mechanism of the node model in low-frequency cyclic loading test.For the concrete beam-column joints,There are 4 processes of crack development of joints,which are the initial crack,the crack,the limit and the damage.and characterized by clear plastic hinge damage.For the steel beam,main beam end bending failure occurred,the model core shear failure and column top bending failure forms of damage.Inner posted plate taken the core of high shear stress,and stress will be passed to the core area of concrete,and slow down the speed of cracks in concrete.(2)Analyzing hysteresis curve,skeleton curve,strength and stiffness degradation curves,displacement ductility factor and equivalent viscous damping factor,received the evaluation of seismic performance of each node.Hysteretic curves of concrete beam-column joints are full,displacement ductility coefficient and equivalent viscous damping coefficient are bigger than common reinforced concrete structures and steel reinforced concrete structure.And the stiffness degradation curves are concave shape,declined gradually slowed down and tend to converge.Indicate that such forms have good ductility?energy dissipation capacity and lateral resisting ability.(3)While analyzing the influence on seismic behavior of concrete beam-column joints in different change of corbel length,corbel web and flange thickness,axial compression ratio,inner posted plate height,and inner posted plate thickness,as well as axial compression ratio,steel girder web and flange thickness,height and thickness of inner posted plate effect on seismic performance of steel beam.Corbel length and inner posted plate thickness have good improvement on bearing capacity? ductility and energy dissipation capacity of concrete node.Appropriate parameters is conducive to improving bearing capacity and seismic performance of the node on steel beam,but too much is counter-productive.Indicates that the selection of appropriate parameters can improve bearing capacity and seismic performance of the node effectively.Finally,analyzing the issues to be discussed on the basis of summarizing the work,the prospects of the research on this topic are put forward.