The Rigidity Of Bolt-weld Splice Joint Of Steel Frame Columns And Its Effects On Column And Structural Stability Performance

Steel frame column is one of the most important component of steel framed structural system.Due to the restriction of transportation,hoisting and other conditions,steel frame column needs to be assembled in construction site.At present,the splicing of steel frame column usually adopts bolt-weld splice joint,the equal strength method is mainly used to design the splicing joint of steel frame column,there is no clear regulation for the calculation of splicing joint stiffness in the related design specification,the influence of the splicing joint on steel frame column stability and the overall performance of steel frame structure is also not explained.The initial stiffness of bolt-weld splice joint of steel frame column is studied firstly in this thesis,then the influence of the rigidity of splicing joint on the stability of steel frame column and frame structure is discussed on this basis.The main research contents include three parts:(1)The initial stiffness of bolt-weld splice joint of steel frame column.Establish calculation model about the initial stiffness of bolt-weld splice joint of steel frame column,analyze the influence of section size and axial compression ratio on initial stiffness of joint.On this basis give a simplified calculation formula for the initial stiffness of bolt-weld splice joint of steel frame column,and the judgement method of splicing joint rigidity.(2)Stability coefficient and column curves of steel frame splicing column.Compare and analyze the ultimate bearing capacity,axial displacement,lateral displacement,deformation characteristics,failure mode,the variation of load-displacement curve of steel frame continuous and splicing column instability about the weak axis and strong axis.Obtain the stability coefficient of steel frame splicing column instability,the column curves of steel frame splicing column are concluded and summarized finally.(3)The influence of bolt-weld splice joint performance of steel frame column on steel frame stability.Based on the two typical instability forms of no-braced and braced steel frame instability,simulate the buckling mode and failure deformation characteristics of steel frame instability,calculate the effective length factor of steel frame splicing column,and compare the difference between no-braced and braced steel frame instability.This thesis makes a systematic analysis on the joint,component and structure according to the rigidity of bolt-weld splice joint of steel frame columns and its effects on structural performance,and the relevant research conclusions can provide references for specification revision,engineering application and academic research.