Assessment of ply thickness and aluminum foils interleaving on the impact response of CFRP composites designed for cryogenic pressure vessels

Carbon fiber reinforced polymer (CFRP) proved to be the best choice to produce cryogenic pressure vessels coupling a reduced weight with superior mechanical performance. Despite this, CFRPs are prone to fuel leakage due to interconnected matrix cracks resulting from mechanical and thermal stresses. Two strategies were combined in this work to reduce fuel permeability, i.e., increase of plies number and metallic film interleaving, evaluating the cryogenic impact response of these new configurations. At first, the only ply thickness effect was assessed and the hybrid sandwich-like (SL) configuration with traditional CFRP (RC) skins and a thin-ply (TP) core displayed impact and residual flexural properties close to RC ones. Then, the effect of aluminum foils interleaving was investigated, and the interleaved SL configuration displayed higher residual flexural properties than interleaved RC for all temperatures, e.g., the residual flexural strength was 30.3 % higher at room temperature and 14.6 % higher at −70 °C, respectively.