Prediction of stress distributions along the intersection of tubular Y and T-joints

Several sets of stress parametric equations have been derived for fatigue strength assessment of tubular Y and T-joints. Among them, the Hellier, Connolly and Dover (HCD) set is the only one which can provide the whole two dimensional (2D) stress information. However, the HCD characteristic stress distribution equations were derived from the limited number of typical finite element (FE) results and thus may not be able to capture the effects of all joint geometric parameters. As part of a large study including X and DT-joints, comprehensive thin shell FE analyses were carried out for 330 different tubular Y and T-joints and the whole FE result database was used to derive a new set of equations as a function of joint geometric parameters. These equations can be used to predict stress distributions along the intersection and also provide an alternative method for the calculation of the hot spot stress concentration factor (SCF). Furthermore, an improved methodology has been suggested for assessment of stress parametric equations.