Crack initiation and propagation in braided SiC/SiC composite tubes: effect of braiding angle

Yang Chen (1, 2) , Lionel Gélebart (1) , Camille Chateau (2) , Michel Bornert (2) , Andrew King (3) , Cédric Sauder (1) , Patrick Aimedieu (2)

1 SRMA - Service des Recherches Métallurgiques Appliquées
2 NAVIER UMR 8205 - Laboratoire Navier
3 SSOLEIL - Synchrotron SOLEIL

Crack initiation and propagation in three braided SiC/SiC composite tubes with different braiding angles are investigated by in situ tensile tests with synchrotron micro-computed tomography. Crack networks are precisely detected after an image subtraction procedure based on Digital Volume Correlation. FFT based simulations are performed on the full-resolution 3D images to assess elastic stress/strain fields. Quantitative measurements of the crack geometries are performed using a novel method based on grey levels. The results show that braiding angle has no obvious effect on the location of crack onsets (initiation always occurs at tow interfaces), whereas it significantly affects the paths of crack propagation. This work provides an explicit demonstration of the crack propagation scenarios with respect to the mesoscopic fibre architectures.

Mots clés: Ceramic matrix composites; In situ X-ray computed tomography; FFT simulation; Crack detection; Crack propagation scenario

Domaines: Physique [physics]; Mécanique [physics]; Mécanique des matériaux [physics.class-ph]

Yang Chen, Lionel Gélebart, Camille Chateau, Michel Bornert, Andrew King, et al.. Crack initiation and propagation in braided SiC/SiC composite tubes: effect of braiding angle. Journal of the European Ceramic Society, 2020, 40 (13), pp.4403-4418. ⟨10.1016/j.jeurceramsoc.2020.04.060⟩. ⟨hal-02870690⟩