Experimental Study On Mechanical Properties Of Steel Frame Box Section Column Bolt Welded And Flanged Joints

Because of its light weight,uniform material,high strength,excellent plasticity and toughness,steel is widely used in civil and industrial buildings.Steel frame structure system is a commonly used structure system in multi-high-rise building steel structure,and steel frame column is one of the most important components in steel frame structure system.Based on steel frame column flange connection node as the research object,through experiment and numerical simulation analysis of the mechanical properties of the node and practicability are studied,the main contents are as follows:(1)Review of related literature,summarizes the domestic and foreign about the steel frame column connections,flange connection,the research status of bolt welding connection,and research on this article introduces the steel frame column flange connection node,the selected topic significance.(2)By conducting static loading tests on three full-scale specimens of steel frame column flange joints,the failure mode of the joints is analyzed by observing the whole process and failure phenomenon of the joints.The bending moment-displacement curve,section strain distribution diagram and bolt tension change curve of each joint specimen were drawn.The influence of weld size change imposed between flange plates on the mechanical properties of joints was analyzed and studied by comparing the test data.(3)Through ABAQUS software,numerical simulation analysis was carried out on the steel frame column flange connection nodes.The interaction relationship,boundary conditions,mesh division and other steps in the modeling process were introduced in detail,and the rationality of the model is checked by comparison it with the experimental results.On this basis,parameterization analysis can be carried out,seven groups of models were established to discuss the effects of material strength,axial pressure,bolt diameter,steel column thickness,stiffening rib thickness,flange thickness and fillet weld size on the mechanical properties of the joints.(4)According to the yield line theory and T-plate calculation,the yield capacity calculation expressions of steel frame box section column pure bolt flanged joints under the control of flange plate and high strength bolts were derived respectively,and the calculated results were compared with the experimental and numerical model analysis results.In this paper,a method for calculating the bearing capacity of the steel frame with box section column bolt-welded and flanged joints is presented.