Experimental validation and numerical sensitivity analysis of thin-walled composite pressure vessels for compressed-air storage

Type IV composite overwrapped pressure vessels (COPVs) are commonly used for hydrogen and CNG storage. However, thin-walled compressed-air reservoirs for heavy-vehicle braking systems remain underexplored and highly sensitive to winding-angle and thickness variations. This study presents an experimentally validated, manufacturing-consistent numerical framework integrating analytical laminate screening, layer-by-layer layup generation, and progressive damage finite element modelling. Hydrostatic burst tests on carbon- and glass-fibre prototypes are used to validate predictions of mass, burst pressure, and failure location. The framework achieves mass prediction errors below 1.4% and accurately captures failure locations, with burst pressure predictions within 1% for medium- and low-angle configurations and conservatively underestimates for higher angles. Sensitivity analysis identifies ply activation as the dominant driver of mass and a key contributor to burst-pressure variability, while outer plies govern stiffness and strength. The results further demonstrate that winding angle controls damage location and failure evolution, highlighting the importance of layer-wise modelling. The proposed approach provides a reliable and physically consistent tool for the design and optimisation of lightweight COPVs for heavy-vehicle applications.