Skip to Main content Skip to Navigation
Theses

Identification de paramètres élastoplastiques par des essais statiquement indéterminés : mise en oeuvre expérimentale et validation de la méthode des champs virtuels

Abstract : This work deals with the extension of the virtual fields method (VFM) to the identification of elastoplastic constitutive parameters. Theoretical aspects had already been addressed before this work but the experimental validation remained an issue, that is addressed in this thesis. The VFM principle is based on the minimization of an objective function figuring the deviation from equilibrium in the tested specimen. The deviation from equilibrium is assessed through the principle of virtual work, using several simple virtual fields that involve the resultant load. Stresses are evaluated from measured displacement fields on a part of the specimen by a radial return approach. The experimental validation has been carried out using tensile tests on flat thin specimens with two different geometries. The first one is a dog-bone shape with a slowly varying cross section. This geometry leads to quasi-uniaxial, though heterogeneous, stresses in the middle part of the specimen. The six parameters governing the isotropic elasto-plastic constitutive equations of the materials have been successfully identified in this test and the robustness of the method has been analyzed. The second geometry is with two notches, giving rise to heterogeneous multiaxial stresses during the tensile test, thus more complicated than the ones of the first geometry. Some of the parameters identified with this second geometry deviate from the reference values of the tested material. An analysis of different alleged sources of errors is eventually presented for explaining those discrepancies.
Complete list of metadatas

Cited literature [98 references]  Display  Hide  Download

https://pastel.archives-ouvertes.fr/tel-00351682
Contributor : Michel Grediac <>
Submitted on : Friday, January 9, 2009 - 11:19:17 PM
Last modification on : Wednesday, November 29, 2017 - 9:43:29 AM
Long-term archiving on: : Tuesday, June 8, 2010 - 5:35:48 PM

Identifiers

  • HAL Id : tel-00351682, version 1

Collections

Citation

Yannick Pannier. Identification de paramètres élastoplastiques par des essais statiquement indéterminés : mise en oeuvre expérimentale et validation de la méthode des champs virtuels. Mécanique [physics.med-ph]. Arts et Métiers ParisTech, 2006. Français. ⟨NNT : 2006ENAM0026⟩. ⟨tel-00351682⟩

Share

Metrics

Record views

479

Files downloads

6129