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Reference : UMR5521-LAUORG-003
Workplace : GRENOBLE,GRENOBLE
Date of publication : Tuesday, September 22, 2020
Type of Contract : FTC Scientist
Contract Period : 12 months
Expected date of employment : 1 December 2020
Proportion of work : Full time
Remuneration : in between 2648€ and 3054€
Desired level of education : PhD
Experience required : 1 to 4 years
Papers materials are lightweight, renewable, biodegradable and bio-sourced fibrous materials that exhibit interesting specific physical and mechanical properties. They are produced in the form of thin and flat sheets and are widely used for numerous functional or structural applications, e.g., for health or food packaging. One of their main drawbacks is their weak ductility, which drastically restrains their formability. Consequently, paper structures with complex 3D geometries cannot be produced without major difficulties, i.e., without undesirable cracks or wrinkles. Many research efforts are being developed to overcome these problems with several strategies. Ours is to design “super-deformable papers” by (i) starting from standard paper sheets and (ii) structuring them with architectured and fine scale folds. The main objective of the postdoc is to assess the relevance of this strategy and to optimize the paper folding architectures.
For that purpose, the following methodology will be adopted:
- Mechanical tests using various mechanical loadings (uniaxial and bi-axial tension¬-compression, bending), controlled environment (temperature, relative humidity) and kinematical field measurements (SDIC) will be carried out with reference architectured papers in order to analyze their macroscale deformation. In addition, meso and microscale deformation mechanisms will be studied via 3D in situ observations using X-ray microtomography .
- Finite Element simulation will be carried out at mesoscale using representative elementary volumes of the architectured papers to predict their visco-elasto-plastic and anisotropic deformation. The simulation will be first compared with the experimental database and then be used to optimize the architectures.
- PhD in mechanics of materials with expertise in FE simulations (mandatory) and experimental mechanics
- Keywords : Bio-based fibrous materials, architecture materials, FE simulation for structural mechanics/material forming processes , experimental mechanics, 2D/3D imaging for heterogeneous/fibrous materials.
The proposed offer is a part of a research project of the Carnot Institute Polynat (http://www.polynat.eu/fr/) and includes an academic partner, 3SR Lab, a solids mechanics research centre of the CNRS and the University Grenoble Alpes (Grenoble, France, https://3sr.univ-grenoble-alpes.fr/), and an industrial partner, expert in the development of paper-based and other bio-based materials and technologies (Centre Technique du Papier, CTP, http://www.webctp.com). The postdoc project will be located in the ComHet research group of the 3SR Lab, with strong interactions with CTP.
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