Computational modeling of carbon/carbon composites under thermal shock conditions

The influence of thermal shock conditions on the extent of carbon material decomposition and through-thickness compressive stiffness degradation of 2D woven carbon/carbon (C/C) composites is predicted by computational efforts and validated against experimental results. The proposed computational framework consists of two main steps: (a) radiation heat transfer analysis on a meso-scale C/C composite model exposed to thermal shock conditions accounting for the heat flux due to decomposing material; (b) stress analysis to model the carbon stiffness degradation due to oxidation observed in the previous step. This is followed by a through-thickness compression analysis on the meso-scale model to determine the composite compressive stiffness. The predicted oxidation behavior and compressive responses of the meso-scale model under various thermal shock conditions are in good agreement with previously published experimental results for temperatures up to 700 °C. Therefore, the proposed computational framework can be used in the initial design of C/C composites and thermal protection systems. That is, it can potentially be used for modeling other C/C composites by changing the fiber architecture, weave pattern and/or fiber volume fraction.