Micro-macro homogenization of mechanical parameters of porous material

  • Le Mans, Sarthe
  • CDD
  • Temps-plein
  • Il y a 12 jours
Offer DescriptionWe offer a fully funded 3-year PhD position at LAUM, UMR 6613 CNRS. This is a joint degree with KULeuven. Poroelastic materials are used to mitigate both the acoustic and the elastic energies. This energy dissipation relies on visco-thermal and viscoelastic losses, which are inherent to the materials properties of the fluid and solid phases and to their microstructure. Relating the microstucture to the macroscopic behavior of poroelastic materials is therefore of primary importance to design poroelastic materials. Two-scale homogenization [1,2,3] has been widely used to derive effective properties of such bi-phasic materials, principally when the skeleton is rigid [4,5]. The present thesis aims at developing and promoting the twoscale homogenization of the entire poroelastic materials, that is to derive the effective properties of both the fluid and the solid phases from the microgeometry. This microgeometry will then be optimized, graded, or designed to exhibited new behavior in poroelastic materials [6]. In that context, the candidate will use two-level model reduction techniques to reduce expensive numerical models. The first part of the work will consist in realizing a reduced model of an elementary cell by a condensation technique. This reduction will be done on the elementary beams of the elementary cell. A dispersion study will then be carried out to obtain the fundamental solutions (quasi-plane waves) propagating in the structure. An experimental validation phase, using existing test benches, will then be conducted on structures obtained by 3D printing. The second part will aim at setting up a reduced model for an assembly of many reduced elementary cells. Particularly Krylov recycling techniques will be considered. A dispersion study on the assembled structure will show if the reduced model modifies or not the wave properties of the material.[1] J.-L. Auriault, C. Boutin, and C. Geindreau, Homogenization of Coupled Phenomena inHeterogenous Media (ISTE; J. Wiley, 2009).[2 E. Sanchez-Palencia, Non-homogeneous media and vibration theory, Lecture notes in physics(Springer, 1980), Vol. 127, OCLC: 6447016.[3] A. Bensoussan, J.-L. Lions, and G. Papanicolaou, Asymptotic Analysis of Periodic Structures(North-Holland Publishing Company, 1978), Vol. 5[4] C. Perrot, F Chevillotte, and R. Panneton, Bottom-up approach for microstructure optimization ofsound absorbing materials, J. Acoust. Soc. Am. 124, 940-948, 2008.[5] J. Boulvert, T. Cavalieri, J. Costa-Baptista, L. Schwan, V. Romero-García, G. Gabard, E. R.Fotsing, A. Ross, J. Mardjono, and J.-P. Groby, Optimally graded porous material for broadbandperfect absorption of sound, J. Appl. Phys. 126, 175101, 2019.[6] T. Frenzel, M. Kadic, and M. Wegener, Three-dimensional mechanical metamaterials with a twist,Science 358, 1072-1074, 2017.Funding category: Financement de l'Union européenne
Projet Marie-Curie
PHD title: Double doctorat (Le Mans Université / KU Leuven)
PHD Country: FranceRequirementsSpecific RequirementsIf you recognize yourself in the story below, then you have the profile that fits theproject and the research group:
  • I have a master degree in acoustic, physics, mechanical engineering or
mathematics.
  • I am proficient in written and spoken English.
  • I have not had residence or main activities in France for more than 12
months in the last 3 years.
  • During my courses or prior professional activities, I have gathered some
experience with at least one of the following: principles of acoustics, numericalmodeling techniques, or experimental methods in acoustics. I have a profoundinterest for these topics.
  • As a researcher I perform research in a structured and scientifically sound
manner. I read technical papers, understand the nuances between differenttheories and implement and improve methodologies myself.
  • In frequent reporting, varying between weekly to monthly, I show the results
that I have obtained and I give a well-founded interpretation of those results. Iiterate on my work and my approach based on the feedback of my supervisorswhich steer the direction of my research.
  • It is important for me to work as an active team member and I am eager to
share my results to in-spire and being inspired by my colleagues.
  • During my PhD, I want to grow towards following up the project that I am
involved in and representing the research group on project meetings andconferences. I see these events as an occasion to disseminate my work to anaudience of international experts and research colleagues, and to learn aboutthe larger context of my research and the research project.Additional InformationWork Location(s)Number of offers available 1 Company/Institute LAUM UMR CNRS 6613 Country France City Le MansWhere to apply WebsiteSTATUS: EXPIRED

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