Experimental Study And Theoretical Analysis On Side Column Joints Of Tenon-mortise Connected Composite Frames

With the continuous improvement of construction technology and the continuous development of construction industry in the process of housing construction in China,various new components and structural forms are constantly emerging.The steel-concrete composite structure can give full play to the excellent characteristics of the two materials,so that their respective mechanical properties can be fully utilized.At present,it has been widely used in practical engineering projects.In view of this,this paper proposes a new type of outsourced U-shaped steel concrete composite beam-square concrete-filled steel column edge joint based on the common steel-concrete composite structure,i.e.a new type of mortise-mortise joint for composite frame edge joint.In addition,this paper carries out experimental research and theoretical analysis on this kind of joint and puts forward design methods.The main content of this thesis include:Firstly,the research status of U-shaped steel-concrete composite beams at home and abroad is introduced,and the common types and forms of connection joints of U-shaped steel-concrete composite beams and concrete filled steel tubular columns are summarized.Secondly,the monotonic static load tests of the new type of mortise-tenon joint with truncated steel bars under positive bending moment and the steel bar penetrating joint under negative bending moment are introduced.The test results are analyzed and the failure mechanism,load-displacement curve,bending moment-rotation curve and stress-strain curve of the specimens are obtained.Thirdly,the finite element model of the specimens is established by using ABAQUS software,and the finite element calculation results are compared with the test results,which verifies the correctness of the finite element model and provides a solution for the modeling of this type of joints.On the basis of the finite element analysis,the stress mechanism of the joints is analyzed.Then,using the finite element model after calibration,the parametric analysis is carried out.The influences of the main beam height,axial compression ratio,wall thickness of the square steel tube,material strength and whether the negative ribs of the slab are penetrated on the bearing capacity of the joint are analyzed.Finally,based on component method and simple plasticity theory,the ultimateflexural capacity design formulas of composite joints under positive and negative bending moments are deduced,and the cracking moment calculation formulas of composite joints under negative bending moments are deduced based on elasticity theory.The existing experimental data are compared with the theoretical calculation values,and the agreement is good,which can meet the needs of Engineering design.