Parametric study and equation of the maximum SCF for concrete filled steel tubular T-joints under axial tension

Concrete-filled steel tubular joints are increasingly being used for built infrastructure such as bridges and towers. In this study, the variation of the maximum Stress Concentration Factor (SCFmax) with non-dimensional geometric parameters in concrete-filled steel tubular (CFST) T-joints under axial tension has been investigated. A database of the maximum SCFs in CFST T-joints under axial tension is developed based on three-dimensional (3D) finite element (FE) models. The 3D FE models developed using ABAQUS software have been verified using experimental results. Graphs showing variation of the maximum SCF, in CFST T-joints, with non-dimensional geometric parameters have been produced and compared with those for non-filled empty T-joints. A parametric equation for predicting the maximum SCFs in CFST T-joints, a useful parameter for design, has been developed in a multiple nonlinear regression analysis. There is a good agreement between the maximum SCFs predicted by the parametric equation and those determined from the experiments.