Hoop Strain Measurement During a SiC/SiC Ceramic Composite Tube Burst Test by Digital Volume Correlation of X-Ray Computed Tomographs

Abstract Background Silicon carbide-fibre/silicon carbide matrix (SiC/SiC) composites are candidate materials for accident tolerant fuel cladding in light water and advanced gas cooled nuclear fission reactors. The mechanical damage behaviour of ceramic is sensitive to the composite geometry, microstructure loading state. Reliable test methods needed investigate subcritical that affects hermetic properties strength, this requires precise measurements under states representative operating conditions. Objective objective was a novel methodology measure deformation an internally pressurised tube. Methods A burst ground SiC/SiC (filament wound braided) tube, pressurized by radial expansion compressed elastomer insert, observed situ high resolution (synchrotron) X-ray tomography. full field three-dimensional displacements were measured digital volume correlation, with rotation correction applied obtain relative circumferential tube wall first time. Results hoop strain, its spatial variations, determined as function stress showed ovalisation barreling quantity cracking increased tensile but critical crack caused rupture not at location maximum strain. Conclusion Precise during found non-uniform strains distribution cracking, which could influence strength.