[NotiAMCA] post doc position at Lamcos (INSA Lyon)

[Mario Storti]

Víctor Calo (KAUST) nos acerca este llamado para una posición en Lamcos
Lab of INSA-Lyon in Villeurbanne, France.

[El PDF completo se puede obtener aqui
 http://venus.santafe-conicet.gov.ar/~mstorti/tempo/post_doc_NURBS.pdf]

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ISOGEOMETRIC F-BAR PROJECTION METHOD OVER HEXAHEDRAL AND TETRAHEDRAL
NURBS USING THE FEBIO FINITE ELEMENT PACKAGE AND THE IRIT MODELING
ENVIRONMENT.

Context and aims
----------------

The modeling of incompressible materials at large strains such as
rubber is a challenging computational issue. For the efficient design
of industrial parts made out of such materials, for example car door
gaskets, not only is the computational efficiency important but also
the easiness of mesh generation. Indeed, efficient numerical methods
for performing such incompressible simulations require the use of low
order hexahedral finite elements for which no generic automatic mesh
generator is available.

Isogeometric Analysis is a new computational paradigm that was
proposed recently by Hughes et al. [1]. It relies on the geometric
primitives used in CAD and computer graphics. Mainly developed using
Non-Uniform Rational B-Splines, the method uses these functions for
both the geometric description (as it the case in most CAD packages)
as well as for finite element shape functions. IGA has proven to be
very efficient in lots of cases, in particular for incompressible
simulation when coupled with projection methods, see Elguedj et
al. [2] and Lipton et al. [3].  Projection methods can circumvent the
usual incompressible locking of finite element based methods. Their
use within IGA with higher order NURBS provides a robust and efficient
method for such complex numerical simulations.

The main goals of this project are the following:
-------------------------------------------------

* Introduce the NURBS based IGA technology in the open source finite
element package FEBio [4] that has been chosen as the new research
oriented platform of Hutchinson computational research group. This
will be done in collaboration with Gershon Elber from the Center for
Graphics and Geometric Computing of Technion University in Israel. A
close interfacing with Gershon Elber geometric modeling environment
IRIT [5] will be done.

* Implement the F-bar in FEBio for NURBS based IGA. The method will be
extended to multiple patches geometries, and efficient computational
strategies for the calculation of the algorithmic tangent will be
studied.  The initial method based on a strong modification of the
iterative linear solver [2] will be tested as well as simpler and less
intrusive alternatives. The recent ideas proposed by Taylor [6] will
be considered as a starting point.

* Extend the method to tetrahedral based NURBS meshes. For this task a
close collaboration with Gershon Elbers s group will take place. The
Technion group will be responsible for the development of smooth NURBS
across tetrahedral elements. The INSA group will be responsible for
the extension of the F-bar projection method to such meshes. The
milestone in this task will mainly be the definition of the projector
and projection spaces.

Qualifications required
-----------------------

* The application should have a PhD in Computational Mechanics.

* Good knowledge of theoretical and programing concepts of finite
element methods for nonlinear applications.

* Strong programming experience possibly in C++ or other object oriented
languages.

* An initial knowledge of NURBS and/or IGA will be considered as a plus.
Good skills in English (reading, writing and speaking).

Duration and salary
-------------------

The duration for the post-doc is two years (24 months). The position
opens March 1st.  The salary will be of around 2000  net per month.
The postdoc will be based at the Lamcos Lab of INSA-Lyon in
Villeurbanne, France (Rhône-Alpes area). At least one stay of
approximately two weeks in Technion University will take place during
the project.

Contact
-------

Thomas Elguedj (Assistant Professor of Mechanical Engineering,
INSA-Lyon).  thomas.elguedj en insa-lyon.fr, +33 (0) 4 72 43 73 68.

Bibliography
------------

[1] J. A. Cottrell, T. J. R. Hughes, and Y. Bazilevs. Isogeometric
Analysis: Toward Integration of CAD and FEA. Wiley, 2009.

[2] T. Elguedj, Y. Bazilevs, V. M. Calo, and T. J. R. Hughes. B-bar
and F-bar projection methods for nearly incompressible linear and
non-linear elasticity and plasticity based on higher-order NURBS
elements. Computer Methods in Applied Mechanics and Engineering,
197:2732 2762, 2008.

[3] S. Lipton, J. A. Evans, Y. Bazilevs, T. Elguedj, and
T. J.R. Hughes. Robustness of isogeometric structural discretizations
under severe mesh distortion. Computer Methods in Applied Mechanics
and Engineering, 199(5:8):2297 2317, 2009.

[4] FEBio web page http://mrl.sci.utah.edu/febio-overview, visited
01/13/2011.

[5] IRIT web page http://www.cs.technion.ac.il/~irit/, visited
01/13/2011.

[6] R. L. Taylor, Isogeometric analysis of nearly incompressible
solids. International Journal for Numerical Methods in Engineering,
doi: 10.1002/nme.3048.
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