   A micro-meso-model of intra-laminar fracture in fi ber-reinforced composites based on a Discontinuous Galerkin/Cohesive Zone MethodWu, Ling  ; ; et alin Engineering Fracture Mechanics (2013), 104 The recently developed hybrid discontinuous Galerkin/extrinsic cohesive law framework is extended to the study of intra{laminar fracture of composite materials. Toward this end, micro-volumes of di erent ... [more ▼] The recently developed hybrid discontinuous Galerkin/extrinsic cohesive law framework is extended to the study of intra{laminar fracture of composite materials. Toward this end, micro-volumes of di erent sizes are studied. The method captures the debonding process, which is herein proposed to be assimilated to a damaging process, before the strain softening onset, and the density of dissipated energy resulting from the damage (debonding) remains the same for the di erent studied cell sizes. Finally, during the strain softening phase a micro{crack initiates and propagates in agreement with experimental observations. We thus extract a resulting mesoscale cohesive law, which is independent on the cell sizes, using literature methods. [less ▲] Detailed reference viewed: 55 (16 ULg) A two scale anisotropic damage model accounting for initial stresses in microcracked materialsLevasseur, Séverine ; Collin, Frédéric ; Charlier, Robert et alin Engineering Fracture Mechanics (2011), 78 In a recent study [15], we proposed a class of isotropic damage models which account for initial stresses. The present paper extends this approach to anisotropic damage due to growth of an arbitrarily ... [more ▼] In a recent study [15], we proposed a class of isotropic damage models which account for initial stresses. The present paper extends this approach to anisotropic damage due to growth of an arbitrarily penny-shaped microcracks system. The basic principle of the upscaling technique in the presence of initial stress is first recalled. Then, we derive a closed-form expression of the elastic energy potential corresponding to a system of arbitrarily oriented microcracks. It is shown that the coupling between initial stresses and damage is strongly dependent of the microcracks density and orientation. Predictions of the proposed model are illustrated through the investigation of the influence of initial stresses on the material response under non monotonous loading paths. Finally, by considering a particular distribution ofmicrocracks orientation, described by a second order damage tensor, it is shown that the model is a generalization of the macroscopic damage model of Halm and Dragon [9], for which a physically-based interpretation is then proposed. [less ▲] Detailed reference viewed: 28 (12 ULg) |
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