Study On The Seismic Performance Of New Type H-beam To Square Tubular Column Connections With Splicing Outer Sleeve

At present,the assembly of steel structure housing industry is developing at high speed,the problems of traditional beams and columns in the form of too many welds,on-site construction difficulties and poor seismic performance and other issues have been highlighted,effectively need to make breakthroughs in the new node,and through a large number of experimental and theoretical research to promote the development of new nodes to meet the needs of engineering practice.Aiming at the present situation,this paper improves the construction of a new type of steel pipe column-H steel beam spliced outer sleeve joint,and carries on the research work of the node in the way of full test and numerical simulation,and the hysteretic behavior,bearing capacity,stiffness,strength degradation,displacement ductility and energy dissipation of nodes under low cyclic loading are studied,and the influence of different influence parameters on the seismic performance of the joints is analyzed,and a more reasonable suggestion is put forward for the node structure.The hysteretic behavior,stiffness degradation,strength degradation,ductility,energy dissipation capacity,stress-strain law,failure characteristics and mechanism of the joints were studied by quasi-static tests on the modified foot-beam joints.The results show that the hysteresis curve is full,the stiffness degradation is relatively stable,the ductility is better,the energy dissipation capacity is excellent,and the improvement measures for the new nodes are effective.The nonlinear finite element model of the node was established by ABAQUS finite element analysis software.The characteristics of nodal failure,hysteretic behavior,nodal bearing capacity,stiffness degradation,intensity degradation,ductility and energy dissipation were studied.The numerical simulation results were compared with the physical test The results show that the results of the finite element method are in good agreement with the experimental results.The new nodal failure modes include: the buckling of the column wall,the flange collapse of the outer sleeve and the connection of the grooved beam to the weld failure and the beam section H-type steel beam plastic hinge damage three forms;The influence of different parameters on the seismic performance and failure mode of the joints is analyzed by finite element numerical calculation.The main contributions are as follows: axial compression ratio,head cover thickness,groove beam thickness,angle steel and stiffener plate thickness and jacket The results show that the key impact parameters are axial compression ratio,angle steel and stiffener plate thickness and outer sleeve thickness.The axial bearing ratio has a great influence on the ultimate bearing capacity of the joints,and the ultimate bearing capacity of the joints with larger axial compression ratio is larger;the influence of the thickness of the angle steel and stiffener plate and the thickness of the outer sleeve on the stiffness of the joints The greater the thickness of the joints,the greater the stiffness of the joints;the axial compression ratio,the thickness of the head cover,the angle of the steel and stiffener and the thickness of the outer sleeve are greater for the ductility of the joints;the angle and stiffener The thickness of the sleeve has a great influence on the energy dissipation capacity of the joint.The axial compression ratio,the angle steel and stiffener plate thickness and the thickness of the outer sleeve have the greatest influence on the change of the joint failure,and increasing the plate thickness effectively displaces the plastic hinge.Finally,combined with the results of test and finite element analysis,the relevant design suggestions are put forward for the new nodes,including controlling the axial compression ratio of the column,increasing the thickness of the angle steel and stiffener and the thickness of the outer sleeve,and forming the outer sleeve and the groove beam And the angle steel and stiffener to shape,to improve the mechanical properties of new nodes and to facilitate the assembly of nodes applications.