ABSTRACT
Full scale fatigue tests on tubular joints have shown that as a crack propagates through the chord wall, it curves under the weld toe. This curvature has been largely ignored in previous numerical studies, due to the extreme complexity of modelling such a situation, with simplified crack geometries modelled and assumptions made about the crack driving force. This paper reports a numerical investigation into crack curvature. Three-dimensional solid finite elements were employed to explicitly model doubly curved semielliptical weld toe cracks in tubular joints. The results agree well with existing experimental data and give a clearer understanding of why cracks in tubular joints exhibit this behaviour. A method of predicting such curvature is also presented.
