Skip to Main content Skip to Navigation
Theses

Méthode de couplage multi-échelles entre simulations numériques polycristallines et mesures de champs pour l'identification des paramètres de lois de comportement et de fissuration des matériaux métalliques. Application à l'étude des alliages TiAl.

Abstract : The aim of this study is to better understand the influence of microstructure on the mechanical behaviour of titanium aluminides, and especially their poor ductility at room temperature. In order to reach this objective, a coupling between full-field measurements and polycristalline finite element calculations has been developed and analysed. With this methodology, strain field measurements cans be compared directly to the results of finite element simulations on the real microstructure, thus permitting the identification of the parameters of the constitutive law. This thesis presents the results of multi-scale strain measurements obtained by compressive tests on four kinds of titanium aluminides. These measurements show influence of chemical composition and processing route on strain measurements depending on the measurement scale. Crack propagation analyses at the grain scale are also performed on the four microstructures by using four point bending tests inside a scanning electron microscope. The validation of the methodology is partially carried out. It is shown that a mesh created by an extrusion of the surfacic microstructure can be sufficient for the identification of the constitutive law when the experimental displacements are imposed as boundary conditions. The applicability of the same methodology to the analysis of crack propagation inside microstructures is also studied by introducing cohesive zone elements in the finite element simulations.
Complete list of metadatas

https://pastel.archives-ouvertes.fr/tel-00116358
Contributor : Eva Héripré <>
Submitted on : Sunday, November 26, 2006 - 8:48:06 PM
Last modification on : Friday, October 23, 2020 - 4:48:01 PM
Long-term archiving on: : Tuesday, April 6, 2010 - 8:03:58 PM

Identifiers

  • HAL Id : tel-00116358, version 1

Citation

Eva Héripré. Méthode de couplage multi-échelles entre simulations numériques polycristallines et mesures de champs pour l'identification des paramètres de lois de comportement et de fissuration des matériaux métalliques. Application à l'étude des alliages TiAl.. Mécanique [physics.med-ph]. Ecole Polytechnique X, 2006. Français. ⟨tel-00116358⟩

Share

Metrics

Record views

846

Files downloads

2596