Abstract
In this work we present 3D FEM analyses of pipes with external surface cracks, loaded in tension both with and without internal pressure. The outer diameter, D, is 400mm and wall thickness, t, is 20mm. Three different crack depths and crack lengths are investigated. The dimensions of the cracks are chosen such that they are representative examples for possible girth weld defects. Ductile tearing is taken into account using the so-called Gurson-Tvergaard-Needleman model. The value for the initial void volume fraction parameter was chosen to represents a realistic crack growth resistance found for X65 pipeline-steel. The FEM model was solved using Abaqus Explicit The results show how variations in crack lengths and crack depths, influence the strain capacity of the pipe. Further, the results show a reduction in strain capacity with increasing internal pressure level.