Finite Element Analysis And Experimental Study On Bearing Capacity Of Intersecting KX-type Welded Joints With Rectangular Hollow Sections

With application of large-span steel structures,rectangular hollow sections(RHS)steel structures have also been practiced more widely.As the main bearing member,RHS has excellent mechanical properties for resisting compression,bending and torsion.Besides,RHS welding joints has been widely applied due to its simple structure,convenient processing and lower cost.However,current research on those joints still lags behind that of circular hollow section(CHS)joints,and has not kept pace with its application,which limits the popularization of RHS steel structures to a certain extent.For RHS steel structures,bearing capacity of its joints is one of the most important contents of its structural design.It is of great significance to improve the reliability of the structure and improve the overall mechanical performance of RHS steel structures.The theoretical research on spatial intersecting joints is less than that of the plane intersecting joints while theoretical research of spatial KX-type welded joints used in RHS steel structures(KX-joints)is rarely reported.The load and boundary conditions of steel tube joints are complex,and the solution of partial differential equations is very difficult.For bearing capacity of KX-joints to be studied in this paper,the analytical method is limited,while experimental research and finite element simulation are more convenient.As a result,the main content of this paper is as follows:Characteristics and development of RHS steel structures and research of RHS welded joints at home and abroad were summarized in the first chapter.The basic theories about bearing capacity of such joints were discussed in the second chapter.In the third chapter,two full-scale tests study on RHS welded joints were introduced in detail.Bearing capacity test the failure mode of such joints were obtained.Experimental and finite element results were compared in the fourth chapter.In the fifth chapter,the influence of bending moment,shearing force and axial force on the bearing capacity of KX-joints were obtained by numerical analysis,and the influence coefficient was calculated.Lastly,a comprehensive summarize was given to the paper and the author made the prospects for future work in the end.This paper enriches studies on bearing capacity of KX-joints under complex load conditions.The experimental research and finite element analysis results have active guidance meaning and applied value to the engineering practice.