Abstract: To enhance the load-bearing capacity and operational safety of type Ⅲ hydrogen storage cylinders, this study focuses on addressing the stress concentration caused by fiber accumulation in fixed-angle winding. Utilizing an optimized design method of expanded-aperture winding, the layup scheme of the cylinder’s winding layers was investigated. Finite element models of the cylinder were developed using ABAQUS-WCM software to analyze stress distribution patterns and their effects on load-bearing performance before and after aperture expansion. The results demonstrate that adjusting the fiber winding aperture reduces stress in the hoop winding layers, increases stress in the helical layers, mitigates stress concentration, and achieves a more uniform stress distribution between the two types of layers. Failure analysis based on the maximum stress failure criterion revealed that the minimum burst pressure increased from 100.1 MPa to 103.4 MPa after aperture expansion, representing a 3.3% enhancement and improved fiber load-bearing capacity. Both hoop and helical winding layers play a more significant role in stress distribution across multiple directions, thereby enhancing the overall structural strength and performance of the cylinder.

Key words: composite hydrogen storage cylinders, flare winding, finite element analysis, layer optimization, stress distribution