In this lab-course, the students will go from the 3D imaging of a simple fibrous material using X ray-tomography, to the computation of its overall permeability and its evolution when deformed,
using numerical simulation.
The participants will experience on a full case study the key steps to collect images in a real situation, digitise and incorporate them into a numerical model to eventually simulate a behaviour and predict the evolution of key physical quantities. In this case study, solid and fluid mechanics are coupled.
This lab-course can be attended by M2 students with a background in solid and fluid mechanics and imaging techniques.
Full case study of the fluid-microstructure coupling in fibrous media: 3D imaging of a woven fabric under deformation using X ray tomography and modelling
of the deformation for the numerical solving of the permeability at the material scale
8 hrs session
A woven fabric will be subjected to a tensile loading with a mechanical testing machine placed inside a X-ray microtomograph, allowing the 3D in situ observations of the fibrous microstructure during its deforrmation. The microstructure will then be finely characterized using 3D image analysis subroutines provided by the freeware ImageJ (Fiji). Therefrom, the permeability of the initial and deformed fibrous reinforcements will be estimated from fluid flow simulation inside the imaged fibrous microstructures using a finite volume CFD software (GeoDict).
The aim of this module is to emphasize the interest of coupling 3D imaging and fine scale fluid flow simulation to estimate both the microstructures and the permeability of fibrous reinforcements commonly used in fiber reinforced composites or geotextiles.