SCF distribution along the weld toe in tubular X-joints reinforced with doubler plates subjected to axial loading: Study of geometrical effects and design formulation

<p>Although tubular X-joints are quite common in offshore structural design and despite the crucial role of stress concentration factors (SCFs) in evaluating the fatigue performance of tubular joints, the SCF distribution in X-joints reinforced with doubler plates has not been investigated so far and no design equation is currently available to predict the distribution of chord-side SCFs along the weld toe of brace-to-chord intersection in this type of joint. In the present research, data extracted from the stress analysis of 81 finite element (FE) models, verified using available numerical results, was used to study the effects of geometrical parameters on the chord-side SCF distribution along the weld toe in doubler-plate reinforced tubular X-joints subjected to axial loading. Parametric FE study was followed by a set of nonlinear regression analyses to develop a new SCF parametric equation for the fatigue analysis and design of axially loaded tubular X-joints reinforced with doubler plates.</p>