Étude des phénomènes d'instabilités, bifurcation et endommagement en mise en forme des matériaux

Abstract : The aim of the present work is to predict the occurrence of plastic instabilities (diffuse and localized necking) in thin sheet metals. The prediction of these plastic instabilities is undertaken using an elastic–plastic model coupled with ductile damage, which is then combined with various plastic instability criteria theory. The bifurcation-based criteria and the maximum force criterion used in this work are formulated within a general three-dimensional modeling framework, and then applied for the particular case of plane-stress conditions for sheet metals. Some theoretical relationships or links between the different investigated necking criteria are established, which allows a hierarchical classification in terms of their conservative character in predicting critical necking strains. The resulting numerical tool is implemented into the finite element code ABAQUS/Standard to predict forming limit diagrams, in both situations of a fully three-dimensional formulation and a plane-stress framework. This approach, that combines constitutive equations to necking criteria, serves as a useful tool in the design of new materials with improved ductility
Complete list of metadatas

Cited literature [138 references]  Display  Hide  Download

https://hal.univ-lorraine.fr/tel-02096987
Contributor : Thèses Ul <>
Submitted on : Thursday, April 11, 2019 - 4:52:53 PM
Last modification on : Tuesday, May 28, 2019 - 3:40:17 PM
Long-term archiving on : Friday, July 12, 2019 - 3:36:07 PM

File

DDOC_T_2018_0217_BOUKTIR.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-02096987, version 1

Citation

Yasser Bouktir. Étude des phénomènes d'instabilités, bifurcation et endommagement en mise en forme des matériaux. Mécanique des matériaux [physics.class-ph]. Université de Lorraine; École Militaire Polytechnique (Alger), 2018. Français. ⟨NNT : 2018LORR0217⟩. ⟨tel-02096987⟩

Share

Metrics

Record views

72

Files downloads

68