Évaluation de la dispersion des propriétés mécaniques d’un matériau composite par sous-échantillonnage

Abstract

This article presents a subsampling and homogenization technique developed to depict behaviour variability at mesoscopic scale in composite materials. This variability is intended to feed multiscale modelling at mesoscale. The technique presented here is meant to characterize the transverse behaviour of unidirectional plies in a stratified Polymer Matrix Composite. A Finite Element Method simulation is performed at microscopic scale considering the heterogeneous media, the mesh being constructed from a transverse micrograph. A part of the ply entitled the sample and supposed to be representative of the material is studied under plane strain hypothesis. A unique loading simulation, reduced to three basic load cases, is applied. Subsamples taken into the simulation cell are homogenized at post-processing level of strain and stress fields. A standard mechanics approach was considered. Various subsampling schemes are performed with various size and spatial distribution to generate statistical distributions of effective elastic properties. Some statistical aspects are highlighted and discussed.