Investigation of mechanical properties and transverse crack onset of thin-ply carbon-fiber composites in ambient and cryogenic conditions with varying fiber types

Transverse microcracking is a critical failure mode in carbon fiber-reinforced polymers (CFRPs) used in linerless cryogenic storage systems, yet reliable prediction of crack onset in cryogenic environments remains challenging. This study investigates CFRP laminates with different fiber moduli and ply thicknesses, and applies the LaRC03 embedded ply failure criterion to predict transverse crack initiation at 296 K and 77 K. The necessary engineering constants (energy release rates, tensile moduli, shear moduli) were measured for each system in both environments and used in the model. Results show that intermediate modulus fibers provide the best balance of toughness and modulus, providing the greatest resistance to 90° ply microcracking under cryogenic conditions. High-tenacity fibers improve resistance to opening-mode cracks but are more prone to shear-driven damage, especially at 296 K where deformation levels are higher. High-modulus fibers presented lower transverse crack onset strength in both environments due to inherent brittleness. Fiber diameter also affects crack initiation through its influence on the ply thickness-to-fiber diameter ratio. The LaRC03 model correlated well with experimental results in both environments, with greater agreement for laminates at 77 K testing.