Damage investigation and modeling of 3D woven ceramic matrix composites from X-ray tomography in-situ tensile tests

Abstract

International audienceThe present paper proposes an investigation of the failure events in a melt-infiltrated SiC/SiC composite. In-situ X-ray microtomography tensile tests were performed at room temperature and at 1250 • C in air. Digital Volume Correlation has been used to identify the damage mechanisms within the material at increasing loads and to propose a damage scenario. Realistic finite element meshes have been constructed from the 3D images to numerically reproduce the experiments at the meso-scale. Elastic simulations exhibit stress concentrations in the planes containing the weft tows. The first cracks and subsequent damage localization were found to appear within these planes thanks to the analysis of the in-situ tomographic data

Analysis of the damage initiation in a SiC/SiC composite tube from a direct comparison between large-scale numerical simulation and synchrotron X-ray micro-computed tomography

“…Firstly, both SiC fibers and matrix are commonly considered as isotropic materials (see e.g. [16,56]). Although the SiC matrix exhibits an anisotropy resulting from the CVI process, the elastic modulus of -SiC varies moderately in different crystallographic directions (face-centered cubic system), hence the assumption of isotropic elastic property of SiC matrix can be admitted (Chapter 3 in [57]).…”

“…Even though the DVC technique has been proved to be able to provide real macroscopic boundary conditions in similar material [16], the accuracy and spatial resolution of the DVC-measured displacement is highly depending on the available image contrast. The latter is not sufficient (e.g.…”

“…In situ X-ray micro-computed tomography (µCT) testing is a powerful tool to experimentally observe cracks within a material, and provides volume information about both the microstructure and the microcrack networks [12,13]. Crack evolution, such as growth path, can be studied with respect to the 3D microstructure [10,[14][15][16].…”

Variational segmentation of textile composite preforms from X-ray computed tomography

“…These numerical twins would be of paramount importance, for example, to fully analyze results of in situ tests, and to better understand the link between the woven architecture and the damage initiation in CMC, see e.g. [30].…”

“…A promising approach was recently proposed by Mazars et al [30] to overcome this obstacle: it consists in combining a priori geometric informations within an image-based approach. In a first step, a limited collection of yarn cross-sections is contoured manually.…”