Stage M2 – Identification of the mechanisms governing the effective elastic properties of polydisperse random fibrous media

The effective elastic properties are key parameters governing the soundproofing properties of fibrous materials used for example in the automotive and building industries. However, the local geometry features governing the overall elastic properties involved in the determination of the final performances such as the transmission loss are yet poorly understood. Several microstructural parameters characterizing the morphology of a random fibrous medium are involved in the macroscopic behavior: distribution of fiber diameters, radius of curvature, the contact between fibers. Identifying the relative contribution of each of these microstructural features to the overall effective elastic properties, is a key step, towards proposing structure- property relationships — between the microstructural descriptors of the composite non-woven and the macroscopic parameters characterizing the propagation of sound waves through
random fibrous media. The present internship, leading to a PhD position, is part of a larger research project aimed at improving our understanding of the relationships between structure-properties-manufacturing processes of porous materials. The consortium consists of two academic institutions and one industrial partner, bringing together experts in elasto-acoustic insulation. The project is based
on the consortium’s recognized expertise in (i) advanced characterization techniques for the acoustic properties of porous media, (ii) numerical homogenization methods that enable the construction of detailed structure-property databases and the development of numerical modeling tools for the creation of highly efficient insulating materials in a wide range of applications (decarbonized transportation, sustainable construction).

In the aforementioned project, a multiscale approach is considered for simulating the effective elastic properties of polydisperse composite fibrous media. The intern will first examine the numerical methodologies published in the literature to derive the elastic constants characterizing a random fibrous medium exhibiting transverse isotropy. Once the appropriate
methodology has been selected, it will be implemented and the corresponding numerical results compared with experimental data. The model will be enriched by using morphological features (fiber diameters, curvature radii, nature of the contacts between fibers) with the aim of identifying a representative volume element. We invite individuals who are rigorous, motivated, creative, and hard-working to join us in this exciting opportunity to develop their research abilities within a top-level research environment equipped with advanced laboratory infrastructures.

More informations on the link below.