General information
Organisation
The French Alternative Energies and Atomic Energy Commission (CEA) is a key player in research, development and innovation in four main areas :
• defence and security,
• nuclear energy (fission and fusion),
• technological research for industry,
• fundamental research in the physical sciences and life sciences.
Drawing on its widely acknowledged expertise, and thanks to its 16000 technicians, engineers, researchers and staff, the CEA actively participates in collaborative projects with a large number of academic and industrial partners.
The CEA is established in ten centers spread throughout France
Reference
SL-DAM-24-0747
Direction
DAM
Thesis topic details
Category
Engineering science
Thesis topics
Multiscale analysis of plastic strain localization under laser driven shock loading
Contract
Thèse
Job description
The localization of plastic deformation in expanding metal shells has been studied for several years in CEA/DAM. In addition to explosively driven shells, the laser driven expansion of thin metal sheets yields biaxial tension conditions representative of shell pieces. This kind of set-up is being developed in CEA/DAM and generates strain rates around 10000/s on sheet parts of centimetric width. The evolution of the experimental set-up to millimetric geometries will allow to reach higher stretching rates, unexplored up to now. For all these geometries, for which the sheet thickness is low with respects to the grain size, the influence of the material microstructure is probably significant and the deformation process shall be analyzed at this scale.
The aim of this PhD work is to study plastic strain localization in a sheet of a body centered cubic (BCC) metal under laser shock loading. The phenomenon will be investigated with finite element simulations incorporating the physics at the mesoscale: plastic slip and twinning. An homogenized polycrystalline approach, using an isotropic constitutive model with mean dislocation density as an internal state variable, and a full field approach including grains, their crystal orientations and slip systems, will be compared.
University / doctoral school
Sciences Mécaniques et Energétiques, Matériaux et Géosciences (SMEMaG)
Paris-Saclay
Thesis topic location
Site
DAM Île-de-France
Requester
Position start date
01/09/2024
Person to be contacted by the applicant
DENOUAL Christophe christophe.denoual@cea.fr
CEA
DAM Ile-de-France
CEA DAM Ile de France
Bruyères-le-Châtel
91297 ARPAJON Cedex
01 69 26 40 00
Tutor / Responsible thesis director
DEQUIEDT Jean-Lin jean-lin.dequiedt@cea.fr
CEA
DAM/DPTA//DPTA
CEA-DAM Ile de France
Bruyères-le-Châtel
91297 Arpajon Cedex France
01.69.26.40.00
En savoir plus