https://hal-polytechnique.archives-ouvertes.fr/hal-02043670Pham, Tuan-HiepTuan-HiepPhamEDF - EDFLaverne, JérômeJérômeLaverneLAMSID - UMR 8193 - Laboratoire de Mécanique des Structures Industrielles Durables - CEA - Commissariat à l'énergie atomique et aux énergies alternatives - CNRS - Centre National de la Recherche Scientifique - EDF R&D - EDF R&D - EDF - EDFMarigo, Jean-JacquesJean-JacquesMarigoLMS - Laboratoire de mécanique des solides - X - École polytechnique - Mines Paris - PSL (École nationale supérieure des mines de Paris) - PSL - Université Paris sciences et lettres - CNRS - Centre National de la Recherche ScientifiqueA generalisation to cohesive cracks evolution under effects of non-uniform stress fieldHAL CCSD2018cohesive zone modelstress gradientcrack evolution[PHYS.MECA.SOLID] Physics [physics]/Mechanics [physics]/Solid mechanics [physics.class-ph]Marigo, Jean-Jacques2019-06-04 10:30:192022-10-22 03:45:272019-06-04 17:24:16enJournal articleshttps://hal-polytechnique.archives-ouvertes.fr/hal-02043670/document10.15625/0866-7136/13499application/pdf1The aim of the present work is to study the stabilizing effect of the non-uniformity of the stress field on the cohesive cracks evolution in two-dimensional elastic structures. The crack evolution is governed by Dugdale's or Barenblatt's cohesive force models. We distinguish two stages in the crack evolution: the first one where all the crack is submitted to cohesive forces, followed by a second one where a non cohesive part appears. Assuming that the material characteristic length d c associated with the cohesive model is small by comparison to the dimension L of the body, we develop a two-scale approach, and using the complex analysis method, we obtain the entire crack evolution with the loading in a closed form for the Dugdale's case and in semi-analytical form for the Barenblatt's case. In particular, we show that the propagation is stable during the first stage, but becomes unstable with a brutal jump of the crack length as soon as the non cohesive crack part appears. We discuss also the influence of all the parameters of the problem, in particular the non-uniform stress and cohesive model formulations, and study the sensitivity to imperfections.