Research On Static Behavior Of Unstiffened Overlapped Circular Hollow Section K-Joints

Steel tubes have been widely used in span truss structures because of excellent properties.As organic component of whole structure, design of tube-to-tube connections is an importantaspect. Connections between hollow section members are usually configured by welding onemember directly to the surface of the other, where possible, without any stiffening orreinforcing element. Overlapped Circular-Hollow-Section (CHS) K-Joints are widely used inactual projects. In order to ensure the safety of the whole structure, it is necessary toinvestigate static behavior of Circular-Hollow-Section K-Joints in all aspects.The research is carried mainly by nonlinear FE. The dissertation discusses behavior,failure mechanism and ultimate capacity of overlapped CHS K-Joints, the joint geometry onjoint behavior is also been discussed. Firstly,4overlapped CHS K-Joints specimens are beenmade use, and will take a test with them for the studying of the mechanism, the stress andstrain conditions of the CHS K-Joints under static load also will been discussed, at last, aforecast of the possibility of the failure mode been made before the test. Secondly, theultimate capacity of the joints will been discussed by the Finite Element method (FE), theultimate capacity under the test condition will be calculated, by the FE, the stress distributionof the interchange of three braces and the intersect line of tube-to-tube will also beendiscussed. At last, the influence of main geometric parameter--、、 on the failure modeand ultimate capacity is investigated and explained.