Two failure modes of C/SiC composite under different impact loads

C/SiC composites have wide applications in thermal protective structures of spacecraft, whose impact resistance is essential for safe service. As a continuation of the previous experimental work, two failure modes of C/SiC composites under the impact loads of different shapes of projectiles are investigated through numerical simulations. First, based on the analysis of the damage mechanism, a two-part brittle orthotropic constitutive model is proposed by coupling the orthotropic elastic relationship and the equation of state to describe the dynamic impact response of C/SiC to the spherical projectile. Second, owing to a distinctive equivalent hardening failure mode of C/SiC when impacted by the flat flyer, a modified three-part orthotropic constitutive model is proposed, which introduces an additional pseudoplastic sub-model to describe the yield and post-yield responses. Finally, compared with the experimental results, the rationality and accuracy of these two models and their corresponding parameters are illustrated with respect to damage characteristics, stress-strain curves, the shape of the debris cloud, and free surface velocity, using the commercial software Autodyn.