Numerical Analysis Of The Local Rigidity Of Completely Overlapped Tubular Joints

As structure members, the completely overlapped tubular joint has its special advantages of good working property, fabrication of convenience and less cost, which is more and more popular in the filed of offshore structures. Although some research had been carried, the rigidity property of the completely overlapped tubular joint is still not familiar by people.The importance of the research on local rigidity of completely overlapped tubular joints and the research achievement domestic and abroad are commented. Under lap brace loading, there exist through brace axial and bending load that resulting in axial and rotational deformation on the chord wall. These loadings are in general transferred from the lap brace to the chord by the shell bending, beam action or combined shell and beam behavior of the gap element. Local rigidity of the joints is defined according to their local deformation mechanism. In this paper, the influence of geometric parameters on the local rigidity of the completely overlapped tubular joints under basic loading is investigated numerically. Various diameters and wall thicknesses of the chord and the through brace as well as gap sizes between the chord and the lap brace on the through brace surface are analyzed. Then by using the regression analysis method, this paper worked out a group of reasonable rigid parametric equations for the calculation of the local rigid under basic loadings, such as axial loading, in-plane bending and out-of-plane bending.