Perforation of needle-punched carbon-carbon composites during high-temperature and high-velocity ballistic impacts

Thermal protection systems (TPS) used in spacecraft are likely to be subjected to hypervelocity impacts with debris at the reentry stage. The resultant ultra-high heat flow may damage the payload inside the impacted vehicle. Carbon fiber-reinforced carbon matrix composites are promising materials for TPS, however they have not been extensively evaluated in terms of crashworthiness at high velocities and temperatures. This work describes the impact resistance of 3D needle-punched carbon-carbon (NP-C/C) composites using both numerical and experimental methods. A multiscale-based model has been developed to predict the ballistic limit of NP-C/C composites. Impact experiments have been performed with a custom-made two-stage light gas gun system at 1200 degrees C and also higher temperatures. The test results have been used to validate the post-impact state of the targets obtained from the proposed model. The ballistic limits of the NP-C/C composites have also been identified as functions of the impact velocity, the impactor diameter and the target thickness. The predictions are in good agreement with the experimental data. Low-thickness NP-C/C laminates show similar absorbed energies per unit weight exhibited by same-dimension Inconel panels tested under comparable temperature and speed impacts, although the NP-C/C composites weight 4.4 times less than the analogous metallic panels.