Skip to Main content Skip to Navigation
Theses

Experimental and numerical investigation of thermomechanical couplings and energy balance in metallic polycrystals

Abstract : Strain localization and damage criteria of materials and structures are commonly based on a dissipative framework and this work investigates the thermomechanical couplings accompanying the deformation micromechanisms. It is partly based on experimental data obtained previously in the laboratory by Bodelot for a A316L austenitic stainless steel polycrystal. This work takes profit of a multi-technique approach combining, in particular, in-situ kinematic and thermal fields measurements as well as Orientation Imaging Microscopy, profilometry and surface micrography. Different tools have been developed (1) to automatically identify the activated slip systems directly from the surface micrography, (2) to approach the surface emissivity field allowing an accurate determination of the thermal fields with a 30 mK precision, (3) to project raw experimental fields on the microstructure and (4) to allow the modeling of the polycrystal aggregate and its real thermomechanical boundary conditions by using a crystal plasticity framework within the Abaqus FE code. It has notably been shown that the temperature variations provides an easy and accurate estimation of the macroscopic yield stress at the specimen scale as well as the determination of the Critical Resolved Shear Stress at the intragranular scale. In addition, the local kinematic measurements allow the in-situ identification of the activated slip systems. Experimental and numerical energy balances have been conducted and a great influence of the polycrystalline heterogeneity on the energy storage mechanism has been underlined. The proposed methods would help improving physical based dissipative criteria for damage analysis
Document type :
Theses
Complete list of metadatas

Cited literature [30 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00917702
Contributor : Abes Star :  Contact
Submitted on : Thursday, December 12, 2013 - 11:52:09 AM
Last modification on : Tuesday, November 24, 2020 - 2:18:04 PM
Long-term archiving on: : Thursday, March 13, 2014 - 5:00:35 AM

File

Seghir_Rian_DLE.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-00917702, version 1

Collections

Citation

Rian Seghir. Experimental and numerical investigation of thermomechanical couplings and energy balance in metallic polycrystals. Other. Ecole Centrale de Lille, 2012. English. ⟨NNT : 2012ECLI0004⟩. ⟨tel-00917702⟩

Share

Metrics

Record views

684

Files downloads

430