CEMEF PhD 2017: Enhancement of a full field finite element framework to model recrystallization i...

Employer
MINES ParisTech - CEMEF
Location
France
Posted
March 01 2017
Position Type
Full Time
Organization Type
Academia

3-years research study at CEMEF.


The Centre for Material Forming (CEMEF) is one of the research laboratories of MINES ParisTech (top executive French engineering school).


CEMEF studies the materials processings in all their aspects: physics, chemical physics, thermal and mechanical analysis and numerical modelling. Researches are on a large range of materials: metals, synthetic and bio polymers, food stuff, composites and nanocomposites, glass, ceramics…


Thesis work description:


 


DIGIMU is an ANR industrial Chair handled by ARMINES MINES ParisTech and co-funded by ANR and an industrial consortium formed by ArcelorMittal, AREVA, ASCOMETAL, AUBERT & DUVAL, CEA and SAFRAN. This Chair deals with the Development of an Innovative and G lobal framework for the ModelIng of MicrostrUctural evolutions involved in metal forming processes. DIGIMU® is also the name of the resulting software developed by the company TRANSVALOR as a project partner.


Countless products involved in our every-day life rely on vital metal parts. Optimizing these parts requires a knowledge of how materials properties change during forming operations. Although the understanding of the underlaying metallurgical phenomena has improved thanks to the continuous progress of experimental facilities, the interest for increasingly fine and predictive simulations has been recently growing. In this emerging context of “digital metallurgy”, the DIGIMU Chair and consortium have two main objectives. The first one is to develop an efficient multiscale numerical framework specifically designed to take such problems. The second one is to bring the corresponding numerical methods to an industrial level of maturity, by decreasing significantly their computational cost and by validating them against the industrial expertise in the DIGIMU consortium


In order to accurately describe the 3D evolution of polycrystals (recrystallization, phase transformations…), full-field methods such as the phase-field (PF) or the level-set (LS) methods have to be employed. In this context, a new FE numerical framework to model grain growth (GG) and recrystallization (ReX) based on a LS description of the interfaces and meshing/remeshing capabilities has been recently developeda. Nowadays, the LS approach is used for Rex/GG modeling in the context of uniform grids with a finite-difference formulation or in a FE framework on unstructured mesh. LS method is also particularly interesting for the modeling of Smith-Zener pinning.


These PhD works will be dedicated to the enhancement of the existing numerical formalism in order to be able, in a smart and efficient way, to deal with strong and local anisotropies of mobility and grain boundary energy. This aspect is today a big numerical challenge for existing full field numerical approaches. Moreover a new modular crystal plasticity finite element method will be employed/ improved during the PhDb. DRX (see Figure) and SRX phenomema for different austenitic stainless steels will be investigated with these developments and validated thanks to existing experimental results.


Finally, the resulting developments will be prepared for integra-tion in the DIGIMU® software package.



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