Stress concentration factor for tubular CHS-to-RHS Y-joints under axial loads

Tubular CHS-to-RHS Y-joints under axial loads were studied numerically for the determination of stress concentration factors for hot spot stresses. Finite element models with detailed weld profile were setup for tubular CHS-to-RHS Y-joints with various configurations. Hot spot stress was determined based on results of finite element analysis by linear extrapolation method and 1 mm stress method. Stress concentration factors were then calculated and verified by the comparison with related test results. The effects of dimensionless geometry parameters and the brace inclination angle on stress concentration factors were discussed. Empirical formulas were setup for the calculation of stress concentration factors at feature locations of tubular CHS-to-RHS Y-joints, the crown toe, the saddles and the crown heel, by regression analysis. The accuracy and applicability of the proposed empirical formulas were verified.