Gildemyn, Eric (2008) Caractérisation des procédés de fabrication de pièces de securité automobile. optimisation multiobjectifs de la mise en forme. PhD thesis Mécanique - Matériaux, Laboratoire Procédés Matériaux Instrumentation - ERT 1055 "ENDOFORM", ENSAM 2008ENSAM0019 p.153.
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Abstract
ABSTRACT : Automotive safety parts manufactured out of steel sheets are more and more expansive due to the increase in price of raw materials. Moreover, these parts are subjected to increasingly demanding European standards. This is why automobile equipment supplier, such as company DEVILLÉ S.A. are looking to develop numerical tools in order to optimize and predict the behavior of these parts, in-service, by integrating the entire manufacturing process. The work presented here is a contribution to this end. The use of optimization methods, in particular a genetic algorithm called NSGA-2, coupled with CAD and finite elements codes made it possible to improve various cost functions like the maximum material damage value obtained in the part at the time of its design or the maximum effort necessary for unbending, etc. The use of neural networks to reduce the total calculation time has also been studied in this work. These numerical methods require the use of material behavior and damage laws which were the subject of an experimental study as well as the identification of the model parameters. In particular an inverse methodology has been used to reduce the error made during the numerical simulation.
| Item Type: | PhD Thesis (PhD) |
|---|---|
| PhD Supervisor: | Potiron, Alain |
| Date: | 19 November 2008 |
| Board of examiners: | Gelin, Jean-Claude and Bernhart, Gérard and Racineux, Guillaume and Dal santo, Philippe and Fourment, Lionel and Potiron, Alain and Boude, Serge and Moutault, Bertrand |
| Ecole Doctorale: | ED 432 ECOLE DOCTORALE SCIENCES DES METIERS DE L'INGENIEUR |
| Discipline: | Mécanique - Matériaux |
| Collection (Fonds): | Arts et Métiers ParisTech (ENSAM) |
| Institution: | ENSAM |
| Department: | Laboratoire Procédés Matériaux Instrumentation - ERT 1055 "ENDOFORM" |
| Subjects: | 4. Materials Science, Mechanics and Mechanical Engineering |
| Uncontrolled Keywords: | simulation EF, Optimisation, Loi de comportement, Algorithme génétique, Endommagement, Procedés |
| ID Code: | 4895 |
| Deposited By: | Eric GILDEMYN |
| Deposited On: | 17 March 2009 |
Table of content
Introduction----------------------------------------------------------------------------------------- 1
CHAPITRE I État de l'Art ----------------------------------------------------------------------- 3
I.1. Introduction-----------------------------------------------------------------------------------3
I.2. Bilan de l'existant ----------------------------------------------------------------------------3
I.2.1. Problématique industrielle------------------------------------------------------------------------------3
I.2.2. Procédés de fabrication étudiés ------------------------------------------------------------------------5
I.2.3. Méthodes d'optimisation en mise en forme-------------------------------------------------------- 13
I.3. Conclusion et objectifs de la thèse ------------------------------------------------------ 15
CHAPITRE II Les Matériaux et leur modélisation ----------------------------------------17
II.1. Introduction--------------------------------------------------------------------------------- 17
II.2. Les matériaux utilisés --------------------------------------------------------------------- 17
II.2.1. Les aciers à Haute Limite d'Élasticité----------------------------------------------------------- 17
II.2.2. Recherche prospective----------------------------------------------------------------------------- 19
II.3. La plasticité --------------------------------------------------------------------------------- 21
II.3.1. Modèles mécaniques------------------------------------------------------------------------------- 21
II.3.2. Les critères d’écoulement plastique ------------------------------------------------------------- 22
II.3.3. Écrouissage isotrope ------------------------------------------------------------------------------- 26
II.3.4. Écrouissage cinématique -------------------------------------------------------------------------- 32
II.3.5. Écrouissage mixte ---------------------------------------------------------------------------------- 34
II.3.6. Comportement viscoplastique-------------------------------------------------------------------- 34
II.4. Modèles d'endommagement-------------------------------------------------------------- 38
II.4.1. Modèle de Lemaître – Chaboche ---------------------------------------------------------------- 38
II.4.2. Modèle de Gurson – Tvergaard – Needleman------------------------------------------------- 41
II.5. Conclusion----------------------------------------------------------------------------------- 45
CHAPITRE III Procédé de rayonnage -------------------------------------------------------46
III.1. Introduction--------------------------------------------------------------------------------- 46
III.2. Aspect expérimental ----------------------------------------------------------------------- 47
III.2.1. Reproduction du procédé en laboratoire-------------------------------------------------------- 47
III.2.2. Microstructure et Microdureté ------------------------------------------------------------------- 48
III.2.3. Contraintes résiduelles ---------------------------------------------------------------------------- 50
III.3. Aspect numérique-------------------------------------------------------------------------- 54
III.3.1. Modèle numérique --------------------------------------------------------------------------------- 54
III.3.2. Résultats de la simulation – Validation--------------------------------------------------------- 55
III.4. Conclusion----------------------------------------------------------------------------------- 59
CHAPITRE IV Méthodes d'Optimisation et d'Approximation. Généralités.-----------60
IV.1. Introduction--------------------------------------------------------------------------------- 60
IV.2. Bibliographie – Généralités -------------------------------------------------------------- 61
IV.2.1. Méthodes classiques ------------------------------------------------------------------------------- 61
IV.2.2. Les algorithmes génétiques ----------------------------------------------------------------------- 67
IV.2.3. Les réseaux de neurones artificiels (RNA)----------------------------------------------------- 74
IV.2.4. Les surfaces de réponses -------------------------------------------------------------------------- 81
IV.3. Choix des méthodes utilisées ------------------------------------------------------------- 82
IV.3.1. Choix d'un algorithme génétique approprié---------------------------------------------------- 82
IV.3.2. Les Réseaux de Neurones------------------------------------------------------------------------- 90
IV.4. Conclusion----------------------------------------------------------------------------------- 95
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