A finite element model of composite overwrapped pressure vessels (COPV) was established based on
the FE simulation software MSC. Marc. The variations of thickness and winding angle along the meridian in the domes
section were considered during modeling. The element thickness and the principal direction of every unit of the domes
were defined. Then, the influence of defects at different locations with different size on the distribution of displacement,
stress and strain as well as the burst pressure had been studied. The results demonstrate that the defects with
the length of 112 mm or less have little effect on the burst pressure in the domes. While at the middle and transition
section of the liner, the burst pressure decreases with the lowered range of 15% as the length of defect increases. The
stress concentration and maldistribution of displacement, stress and strain generate around the defects. The distribution
of strain is consistent with that of the stress. And the isolines of three directions’ strain are bended around the defect
which affects the bursting pressure as well as the fatigue life.