Parametric Study of Hot Spot Stresses around Tubular Joints with Doubler Plates

Structural designers use parametric equations to convert results of simple beam models to detailed hot spot stress distributions. Knowledge of hot spot stresses improves fatigue performance predictions. This paper extends the use of the parametric equation approach to joints with extra stiffening such as doubler plates. Doubler plates are commonly used on tubular structural joints against actual or anticipated punching shear failure. Reinforced tubular T, Y, K, X, and DT joints with and without doubler plates are considered. Results without doubler plates are compared against past studies and also the recommended design formulas used in international codes. Finally, a sensitivity analysis is performed describing the effect of joint geometry variations on the stress concentration factor values.