Experimental Study On Hysteretic Behavior Of Assembled Joints Of Steel Staggered Truss To Concrete-filled Square Steel Tube Column With Sleeve And End-plate Connection

The staggered truss structure system has attracted much attention at home and abroad because of its high efficiency,economy,practicality and flexible structure.Many scholars have studied it.The available data show that the research of staggered trusses mostly focuses on the overall performance of the structure,and the research on the connected joints of the column and the truss is less.With reference to the existing joint forms,this paper presents a sleeve and end-plate joint with truss and column connection,and studies the force performance of the new joint by experiment and finite element analysis.In this paper,two sleeve and end-plate joint specimens with column and truss are designed with a 1:2 scale ratio.The stress and failure mechanism of the joint specimens are studied by low-cycle loading test.ABAQUS is used to establish the finite element models of joints,and its three-dimensional nonlinear analysis is carried out.By the finite element analysis of the joint parameters,the influence of the parameters such as the axial compression ratio,the concrete strength,the thickness and extension length of the sleeve,the length of the connecting short beam and its flange and web thickness are discussed respectively.The experimental results show that the connecting short beam has a great influence on the bearing capacity of the joint.When strengthening the connecting short beams,the bearing capacity of the joint has greatly improved.This joint form has good deformation and energy dissipation capacity.The finite element analysis shows that the axial bearing ratio has a great influence on the bearing capacity of the joint.The thrust bearing capacity of the joint specimens decreases with the increase of the axial compression ratio,while the pull bearing capacity decreases with the increase of the axial compression ratio.The strength of the concrete,the thickness and extension length of the sleeve,the thickness of flange of the connecting short beam have little effect on the bearing capacity of the joint.The length and the web thickness of the connecting short beam have a great influence on the bearing capacity of the joint,and the force increases with the web thickness of the connecting short beam.