Research On Chs-to-Rhs Joints Based On Finite Element Method:analysis Of Non-Dimensional Geometrical Paramerers And Design Of Fatigue

Metallic hollow section joints have been widely applied to the engineering structures.Due to its excellent mechanical properties and great aesthetic charm the tube structure hasbeen generally used in marine platforms, high-rise structures, building structures, etc.Compared to the tube structure, a joint with a square hollow section tube in chord and witha circular hollow tube in brace not only has the advantages of tube structure, but also hasits own style.Because of a limited number of joint experiments, the convincing results can not beobtained only based on the experimental results. The regressing formula is even moredifficult to get. In this paper, using the finite element analysis software (ANSYS), the hotstress state of CHS-to-RHS T-joints for the different non-dimensional geometryparameters is analyzed. The joints are subjected to the same axial loadings, and theforce-deformation characteristics have been summarized using the charts and excels.This paper investigates the hot spot stress concentration factor of CHS-to-RHST-joint joints, which are subjected to the same axis load for the different non-dimensionalgeometry parameters. In order to use ANSYS to analysis the CHS-to-RHS joints, thepaper first analyzed specimens of the literature, and the results of their finite elementmodeling are compared with experimental data to determine the feasibility andeffectiveness calculations. Since then, this paper had selected three main parameters, i.e.,β,2γ,τ which affect the stress concentration factor. Moreover, their common ranges arealso determined.According to certain rules, author selected a series of non-dimensional geometryparameters and made them all permutations and combinations to build a series of finiteelement modeling. The parameter points evenly distributed throughout the parameterspace, and the non-dimensional geometry parameter of the biggest hot spot stress valuewas found. Then, the law of these parameters is inductively analyzed to guide theproduction practice. This paper specially studies the dimensions of welding foot, and findsthat welding foot size on the impact of stress concentration factor can not be ignored. The different welding foot sizes for the influence of the stress concentration factor should beconsidered in the engineering applications. However, the paper only examines the threemain non-dimensional geometric parameters, β,2γ,τ, in view of this, the paper makes aspecial requirement for the welding foot size on the basis of the norms. It tries to eliminatethe interference for the other three non-dimensional geometry parameters, which can beenabled to adapt to the needs of modeling.Finally, this investigation has regressed out the S-N curve of CHS-RHS T-jointsbased on the fatigue test data.