Hydrogen permeability of thin-ply composites after mechanical loading

Hydrogen is a sustainable alternative to conventional fuels, and it may be obtained with near zero carbon footprint. However, hydrogen storage remains a key challenge, and the use of composite tanks has gained significant interest over the last few years. In addition, thin-ply composites promote fibre damage by delaying matrix microcracking and free edge delamination. In this work, the H2 permeation/diffusion performance of virgin and mechanically loaded thin cross-ply laminates is studied. In addition, Scanning Electron Microscopy (SEM) is used to identify defects and micro-damage in the laminates and explain the experimental values. The study shows that the hydrogen (H2) barrier performances of thin-ply composites are lower than conventional metallic systems. Obtained permeability values, however, resulted well below the allowable limits for most combinations of temperature and pressure and remain unaffected despite the application of high tensile strains showing that permeation is not accelerated.