Labex MEC “Mechanics And Complexity”
Post-Doctoral position offer
Duration: 1 year
Period: June 2014 – May 2015
Location: Marseille, France
Gross salary: from 2423 € to 2843 €/month
depending on qualification and experience
Research project and job description
Title: Coupled Thermo-mechanical Characterization of composite materials based on IR
camera and Digital Image Correlation measurements : Analysis with inverse method of
thermal sources field induced by strain local state in order to describe damaging
mechanisms
Summary: Composite materials composed with thermoset matrix reinforced with glass or carbon
fibers have been designed for their good mechanical properties and low density and are widely
used in aeronautic applications. Under static or cyclic loading, the mechanical behavior is strongly
coupled to the thermal behavior of composite material. The thermo-mechanical behavior can be
complex for visco-elastic or visco-plastic material, composite material are essentially used in elastic
domain, but it seems interesting to investigate these phenomena to have a better understanding of
damaging mechanisms. The self heating of materials is classically observed during an inelastic
deformation in static or cyclic loading. The global behavior of heterogeneous material in elastic
domain can be more complex due to the damaging mechanism at the microstructure scale
(fiber/matrix frictions, apparition of crack in the matrix, fibers rupture,...).
Fig.1. First measurements have been lead on with an IR camera on composite samples in tensile
configuration.
The first measurement related in Fig.1 will be improved to allow a synchronized measurement
between kinematic field (strain field) with a Digital Image Correlation (DIC) system and thermal
field with an accurate IR camera. Then with these data, an adapted inverse method will be
developed to convert the measured thermal field in a thermal sources field synchronized with the
mechanical field measured. This synchronized thermo-mechanical data will be very useful to
understand the different dissipation mechanisms in composite materials (nature of damaging,
matrix dissipation,...).
Job description: The aim of the post doctorate is to set up the experimental system on composite
materials to measure the thermo-mechanical state of the material and its evolution under static or
cyclic loading, to develop an inverse method to have the real thermal sources and finally to write a
thermo-mechanical law taking into account all the phenomena observed, particularly damaging.
Different steps can be considered :

A preliminary bibliographical work : composite damaging under mechanical solicitations,
thermo-mechanical law, experimental field measurement (IR measurement and DIC),
identification method of thermal sources (inverse method, regularization, truncated SVD,
constrained optimization, penalization algorithm,...)

Experimental campaign : definition of composite samples (matrix, fibers, fibers orientation,
plies number,...), loading configuration (tensile, shear, static, cyclic)

Setting up of the experimental device, test and validation

Development of an inverse method to identify the thermal sources field in function of
loading history

Discussion on thermo-mechanical behavior model introducing of damaging model with a
validation on tested samples
References
[1] Hochard C., Miot S., Lahellec N., Mazerolle F., Herman M., Charles J.P. Behaviour up to rupture of woven ply laminate
structures under static loading conditions, Composites Part A: Applied Science and Manufacturing 40 (8) pp 10171023, 2009
[2] A. Maurel-Pantel, E. Baquet, J. Bikard, N. Billon. Coupled thermo mechanical characterisation of polymers based on
inverse analyses and IR measurements. Applied Mechanics and Materials. 70, pp 393–398, 2011
[3] J. Gaspar, J-L. Gardarein, F. Rigollet, C. Le Niliot and Y. Corre, S. Devaux, “Nonlinear heat flux estimation in the JET
divertor with the ITER like wall”, Int. J. of Therm. Sciences, Volume 72, October 2013, pp. 82-91
[4] F. Rigollet, R. Reichle, J. Gaspar, J. L. Gardarein, C. Le Niliot, R. Huxford, « Prediction of spatial resolutions of future IR
cameras at ITER », Quantitative Infra Red Thermography Journal, Vol. 10, issue1, pp 96-111 (2013)
[5] A. Chrysochoos. Infrared thermography applied to the analysis of material behavior: a brief overview, Quantitative
InfraRed Thermography 9 (2) pp 193-208, 2012
[6] S. André, N. Renault, Y. Meshaka, and C. Cunat. From the thermodynamics of constitutive laws to thermomechanical
experimental characterization of a semicrystalline polymer from IR imaging, Continuum Mechanics and
Thermodynamics, vol. 24-1, pp 1-20, 2012.
[7] R. Seghir, J.-F. Witz, L. Bodelot, E. Charkaluk, P. Dufrénoy. An improved lagrangian thermography procedure for the
quantification of the temperature fields within polycrystals, Quantitative InfraRed Thermography 10 (1) pp 74-95,
2013
[8] O. Westphal, L. Gornet, J. L. Bailleul, T. Jurkowski, P. Rozycki, L. Stainier. Behavior under damages and
characterization of mechanical and thermal properties of a carbon fiber reinforced epoxy matrix laminated composite.
18th Journées nationales sur les composites, 2013
[9] N. Renault, S. André, D. Maillet, C. Cunat. A spectral method for the estimation of a thermomechanical heat source
from infrared temperature measurements, International Journal of Thermal Sciences, Volume 49, Issue 8, Pages 13941406, August 2010
[10] N. Renault, S. André, D. Maillet, C. Cunat, A two-step regularized inverse solution for 2-D heat source
reconstruction, International Journal of Thermal Sciences, Volume 47, Issue 7, Pages 834-847, July 2008
[11] M. Naderi, A. Kahirdeh, M.M. Khonsari. Dissipated thermal energy and damage evolution of Glass/Epoxy using
infrared thermography and acoustic emission, Composites Part B: Engineering, Volume 43, Issue 3, April 2012, Pages
1613–1620
[12] J.M. Roche, D. Balageas , P. Lapeyronnie, F. Passilly, A. Mavel. Use of infrared thermography for in situ damage
monitoring in woven composites. Proceedings of the International Conférence on Full Field measurement Techniques
and their applications in experimental solid mechanics, PhotoMechanics 2013
Essential skills:
Engineer or Master in solid or structure Mechanics or Master in physics or thermal engineering
with good skills on material field.
Labex team
Axe 2, action 2.1, item ‘damaging of woven composite : experimental
characterization of thermomechanical behavior law’
Contacts :
Fabrice Rigollet,
mail : fabrice.rigollet@univ-amu.fr,
tel : 04 91 10 68 85
Aix Marseille Université, CNRS, IUSTI UMR 7343, 5 rue E. Fermi, 13453, Marseille,
France
Aurélien Maurel,
mail : maurel@lma.cnrs-mrs.fr,
tel : 04 91 16 42 27
CNRS, LMA UPR 7051, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
How to apply
Send an application including:

A detailed CV with a list of publications

A cover letter

A list of scientific personalities able to comment on the application
to both these addresses:
Relevant group leader (…@...)
Labex management (LabexConseilCoordination@irphe.univ-mrs.fr)