Introduction:
The numerical simulation of metal forming processes with small contact area, such as ring rolling, rolling, drawing, etc. requires developing new algorithms in the FORGE® software, which are the purpose of several Ph. D. research programs on: contact improvement, extension of the A.L.E. (Arbitrary Lagrangian Eulerian) formulation to quasi-steady processes, multi-level meshes. They are developed with the sequential version of the software.

Objectives:
The post doctoral work objectives are to write again some of the newly developed algorithms in order to adapt them to parallel computations. In fact, several days are required to simulate these processes, so the computational time appears to be the main bolt to the use of numerical simulation.

Keywords:
Parallel computations, Domain Decomposition, Contac, A.L.E. formulation, C++

Context of the study:
FORGE® is among the leaders, or the international leader of simulation software for forging and bulk forming simulation. It is continuously developed by CEMEF since the last 25 years, and is marketed by Transvalor since the last 20 years. The parallel version of the software is based on a SPMD (Single Program Multiple Data) approach by mesh partitioning, which required handling the parallel features at a relatively upstream level.

Work program:
The parallelization of new developments will be three-fold:

• Parallelization of contact algorithms: Part of the planned developments is easy to extend to the parallel version of the software. A more specific effort will be required for the integrated (facet-to-facet) contact between deformable bodies: exchange of information between different processors for different bodies. The totally new contact surface smoothing algorithm will have to be made parallel.
• Parallelization of the ALE formulation: The ALE formulation was only developed in the sequential version. It is based on two main operations: mesh velocity calculation and data transfer between the meshes. The parallelization will require changing the computational methods without changing the algorithms that have been properly validated.
  

• Integration of the bi-mesh method: The contact and ALE improvements will be made compatible with the bi-mesh resolution method. In a parallel environment, the speed-up obtained by the combination of the 3 techniques will be evaluated. This work will be carried out in close relationships with the Transvalor company, and in the frame of the CIMLIB library, which is developed in the CIM group in C++. It will be based on clusters of parallel PCs under Windows (9 PCs maximum) or LINUX (up to 500 PCs) environment.
  

Work frame:
This project gathers several industrial partners who fund it: INDUSTEEL Creusot,AUBERT&DUVAL, CEZUS, UGITECH, ASCOMETAL, ArcelorMittal Gandrange, SNECMA, ARCELOR RESEARCH SA, Alcan CRV, TRANSVALOR. The research work will be carried out within the CIM group (Advanced Computing in Material Forming), under the supervision of Lionel Fourment, in close relationships with the 3 Ph. D; students working on the contact improvement, A.L.E. formulation extension, and bi-mesh method, and with a post doctoral fellow using this software for welding applications.
The post doctorate researcher will be involved in the supervision of Ph. D; students.

Salary and place of work:
The gross monthly salary is 2 600 euros. The work will be carried out at Mines ParisTech, Sophia Antipolis, French Riviera. The duration is three years.

Skills and abilities requested:
Structured and Object Oriented Programming, Parallel Calculations, Domain Decomposition methods, Finite Element or Finite Volume methods, Solid Mechanics.

Contact and Information:
Lionel Fourment, CEMEF, rue Claude Daunesse, B.P. 207, O6 904 Sophia Antipolis, France
lionel.fourment@ensmp.fr, tel : +33 4 93 93 75 95 ,
http://www.cemef.ensmp.fr/

To apply:

Send your C.V. by e-mail with the title of the post-doc to: write_email("postdoc","cemef.ensmp.fr");postdoc@cemef.ensmp.fr, lionel.fourment@ensmp.fr

More information:
Lionel Fourment, CEMEF, rue Claude Daunesse, B.P. 207, O6 904 Sophia Antipolis, France
lionel.fourment@ensmp.fr, tel : +33 4 93 93 75 95 ,
http://www.cemef.ensmp.fr/

Founded in 1974, the Centre for Material Forming is one of the 18 research centres of Mines ParisTech. It moved to Sophia Antipolis in 1976 with the will of being involved in the creation of a new high technology science park on the French Riviera. It has been associated with CNRS, the French National Science Foundation, since 1979 (Unité Mixte de Recherche 7635).

• Its mission is threefold :
  • transmission of the knowledge and of the know-how of CEMEF to engineers or researchers during their training at the Centre,
  • research,
  • active collaboration with Industry.

• CEMEF is an European leader in the field of research on materials processing.
  Approximately 130 people - among whom 50 PhD students - are working on research designed to get in depth understanding of forming processes ; these topics are focused around three scientific axes :
  
  • Material flows, tools must resist => thermomechanical axis of continuous media;
  • Material orients, crystallises or forms textures => flow - crystallisation - morphology relations axis;
  • Material exhibits friction on the tools => surfaces and contact mechanics axis;
  • multi-scale modelling for manufacturing processes.
    
    
• CEMEF is largely involved in higher education :

    - two masteres : "Materials and Processing", et "Computational Mechanics", the last one in collaboration with Ecole Nationale des Ponts et Chaussées;
    - one master : "Materials Physics, Mechanics and Numerical Modelisation" jointly with Nice/Sophia-Antipolis University;
    - a postmaster degree in bioplastics
    - two doctorates of Ecole des Mines de Paris "Materials Science and Engineering" and "Computational Mechanics"

• Advanced Computing in Material Forming group: The vocation of the group is to elaborate numerical methods allowing to efficiently solving the problems arising from the numerical simulation in material forming. These studies aim at eliminating major bolts such as computing time, mesh generation or reliability of results. The group activity applies in fields that are genuine numerical challenges, like forging, filling (injection or casting), foaming and process optimisation. Forge3® and Rem3D® are the main software platforms of the group.