Impact Damage Evolution and Residual Strength Assessment of Composite Hydrogen Storage Cylinder

Carbon fiber composite cylinders have been widely applied in onboard hydrogen storage systems due to their excellent strength-to-weight ratio and superior durability. Investigating the influence of the post-impact residual strength is important for ensuring hydrogen cylinders’ safe and reliable utilization in practical applications. In this work, a detailed numerical model was developed for the simulation of cylinder impact behavior and residual strength analysis. The mechanical response, energy dissipation and damage evolution mechanisms under impact were analyzed based on the experimentally validated numerical model. The effects of impact energy, impact location and liner type were thoroughly investigated. A quantitative assessment model of post-impact residual strength of cylinders based on impact damage characteristic parameters was established. The results show that the impact damage manifests as intralaminar damage. The impact resistance of different cylinder regions shows the order of cylindrical region < transition region < dome region. The frictional energy dissipation rate in the dome region is approximately four times that of other regions. The impact resistance of cylinders with different liners shows the order of CY-Al> CY-HDPE≈ CY-PA6. The weakening effect of damage caused by high-energy impacts on the residual strength gradually decreases. The impact damage depth serves as the dominant damage characteristic parameter for the quantitative assessment model of residual strength.