Square Steel Tube Concrete Flange Outer Ring Plate Beam Column Research On Seismic Behavior Of Joints

Concrete-filled steel tube beam-column joints because of its high bearing capacity,good fireproof performance,good ductility performance,economic efficiency and seismic performance significantly,and many other advantages,is widely used in construction field,traditional concrete-filled steel tube beam-column joints of the diaphragm,diaphragm and diaphragm,and column through the outer ring plate of node is given priority to,these nodes in the assembly or more or less inevitably require a certain degree of welding,prefabricated building structure thought based on gradually in recent years were introduced,in this paper,a kind of can achieve almost all bolted flange outer ring assembly of plate concrete beam-column joints in steel tube column,In this way,the seismic performance of concrete-filled steel tubular beam-column joints in the form of this joint is explored,and the test of its low-cycle reciprocating load is carried out.Meanwhile,a systematic study on the joints is carried out by combining numerical simulation with theoretical analysis and calculation.The main research contents and results are as follows:1.The standard specimen of a square concrete-filled steel tube flange outer ring plate beam-column joint is subjected to low-cycle repeated loading test at the column end.The test results show that the standard specimen joint has a full hysteretic curve,high bearing capacity,high energy dissipation capacity and good seismic performance.2.using ABAQUS finite element software first standard node modeling analysis of the test,the simulation nodes in a state under the condition of test load,boundary and contact status,the analysis results show that the finite element numerical results and experimental results are basically consistent,error control within a certain range,prove the feasibility of the finite element model.Then on the basis of the standard node,concrete-filled steel tube flange outer ring plate beam-column joints for seismic performance analysis,on the basis of the standard node,a total of four nodes specimen finite element model is established,through the local increase node domain column wall thickness and the overall increase in the thickness of steel pipecolumn,to examine wall thickness and generous ratio on the seismic performance of the node.The results show that both the local and the overall increases in wall thickness increase the bearing capacity of the joints,enhance the ductility of the joints,and show better seismic performance.3.then the factors that might affect the mechanical properties of the node parameter analysis,the axial compression ratio,respectively after removing the strength of the steel and core concrete factors such as the increase of wall thickness influence on seismic performance of node,the results showed that after removing the strength grade of steel and concrete for the bearing capacity of the node and a greater influence on the seismic performance,axial compression ratio within a certain range can improve the bearing capacity of the node and seismic performance,but after more than a certain limit the impact on the node is no longer significant.