Issue 50

M. Belhamiani et alii, Frattura ed Integrità Strutturale, 50 (2019) 623-637; DOI: 10.3221/IGF-ESIS.50.53 626 The Ramberg–Osgood model was found to represent the relationship accurately, with its parameters extracted from Walker and Williams [21]. Figure 1 : Geometries and dimensins considered in the present work [23]: (a) plane strain pipe with an extended inner axial crack, (b) circumferential through wall cracked pipe, (c) repaired pipe and (d) axial through wall cracked pipe. Figure 2 : Mesh type of the model and reffined crack front for all crack type F INITE ELEMENT MODEL he FE code ABAQUS was used in this work to obtain the stress fields of the pipeline and the J integral versus the longitudinal crack front. The FEM was used to model the cracked pipeline repaired by a wrap composite. The FE mesh for the longitudinal crack is shown in Fig. 2. The pipeline was meshed using a structured mesh with three-dimensional hex- dominated quadratic elements (C3D20R). In order to improve accurately the J integral values calculated from the crack geometry, the simulation on crack zone is performed using the 20-node brick elements with high-level mesh refinement T