Study On Mechanical Properties Of High Strength Tubular Joints

Steel pipe structures are widely used in various building structures because of its good mechanical properties and beautiful appearance.As an important part of the steel pipe structure,the steel tubular joints have complicated geometric structures and forces,and the design of the tubular joints has always been an important research topic in steel pipe structures.At the same time,high-strength steels are also widely used in steel structure engineering,but the mechanical properties of high-strength steel tubular joints are still lack of research.Therefore,in order to obtain the effective and safe application of high-strength steel tubular joints in the actual engineering,it is imperative to study the mechanical properties of high-strength steel tubular joints.The main research work is as follows:(1)The mechanical properties,failure modes and ultimate bearing capacity of high-strength overlapped tubular N-joints are studied by using finite element analysis.By changing the geometric parameters(diameter ratio of branch pipe to main pipe,wall thickness ratio of branch pipe to main pipe,ratio of diameter to wall thickness of main pipe,joint overlap ratio)and load parameters(axial force of main pipe)of the joint to study the influence of each parameters on the ultimate bearing capacity of joint.(2)Based on the research of high-strength overlapped tubular N-joints,the mechanical properties,failure modes and ultimate bearing capacity of the high-strength overlapped tubular planar KT-joints are studied.By changing the geometric parameters(diameter ratio of branch pipe to main pipe,wall thickness ratio of branch pipe to main pipe,ratio of diameter to wall thickness of main pipe,joint overlap ratio)and load parameters(axial force of main pipe)of the joint to study the influence of each parameters on the ultimate bearing capacity of joint.(3)For the high-strength overlapped tubular N-joints,Comparing the finite element calculation results with the formula calculation in the Standard for design of steel structures(GB 50017-2017),and the bearing capacity correction coefficient formula is proposed.For the high-strength overlapped tubular planar KT-joints,referring to the existing joint calculation formula in the code,the ultimate bearing capacity calculation formula of high-strength overlapped tubular planar KT-joints obtained through multivariate linear regression analysis.(4)Using structural analysis software to analyze the deflection,force and stress ratio of the main truss in the truss engineering of comprehensive experimental building of Xiang nan University,and comparing the results of the structural analysis with the standard limits.