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Endommagement ductile des matériaux métalliques sous chargement dynamique - Application à l'écaillage

Abstract : From many years, a very special attention is paid to dynamic fracture in the industrial (forming process, high-speed machining,...), as well as in the medical (laser shock surgery,...) or military (perforation, impact,...) sectors. Ductile fracture has been observed to result from the nucleation, growth and coalescence of voids. The aim of the present work is to develop a ductile damage model for metallic materials subjected to dynamic loading. The material domain is assumed initially free of voids and the nucleation stage is accounted for by a statistical description of potential nucleation sites. When the pressure overcomes a critical value at a given site, a void is appearing spontaneously and starts to grow by plastic deformation of the matrix material. After a preliminary study on different homogeneous schemes describing the macroscopic behaviour deduced from the local behaviour of all unit cells, a “same applied stress” type approach is adopted. It is shown that micro inertia effects are closely related to the damage heterogeneity within the material. It also appears of the utmost importance to take into account the effect of the porosity on the inertial contribution and on the loss of viscoplastic matrix resistive strength. Afterwards, the modelling is implemented in the finite element code ABAQUS/EXPLICIT. Numerical simulations of plate impact experiments are conducted and reveal a good accuracy with experimental data on tantalum material. The proposed work provides a better comprehensive of spalling phenomenon.
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https://tel.archives-ouvertes.fr/tel-00188759
Contributor : Christophe Czarnota <>
Submitted on : Monday, November 19, 2007 - 11:45:39 AM
Last modification on : Monday, April 16, 2018 - 10:42:01 AM
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Christophe Czarnota. Endommagement ductile des matériaux métalliques sous chargement dynamique - Application à l'écaillage. Mécanique [physics.med-ph]. Université de Metz, 2006. Français. ⟨tel-00188759⟩

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