Stress concentration factors for fatigue design of CHS-SHS T-joints

Alternative type of nodal joints consisting of Circular Hollow Section (CHS) braces and Square Hollow Section (SHS) chords (CHS-SHS joints) have increasingly been studied to understand strain distribution and therefore Stress Concentration Factors (SCFs) at weld toes on the braces and chords for fatigue design in structural systems subjected to cyclic loading. Experimental Strain Concentration Factors (SNCFs) for eight CHS-SHS T-joints with unique non-dimensional parameters were determined in this research resulting in the evaluation of SCFs for fatigue design. Using the ANSYS software, a three-dimensional Finite Element Model (FEM) was then developed to simulate the stress distribution at the brace-chord welded interface under axial force and in-plane bending in the brace. A parametric study was carried out to determine the SCFs for numerous models with unique non-dimensional parameters. Graphs are drawn which can be used for the estimation of SCFs in these joints.