Damage analysis of thin 3D-woven SiC/SiC composite under low velocity impact loading

Thin 3D-woven SiCf/SiC samples were subjected to low velocity impact tests at room temperature. For this purpose, hemispherical impactors and circular supports of various diameters were used. The extent of damage was evaluated with the help of optical microscopy. Formation of micro-cracks initiating from the indented site is observed. The predominant internal damages (fiber bundle and matrix cracking) remain localized beneath the impactor. This is confirmed by thermography analysis and post-impact tensile tests. The diameter of the damaged zone can be related to the energy absorbed by the specimen during the impact event.