Closed-form Analytical Model for the Cylinder Region of Thick-Walled Composite Pressure Vessels for Hydrogen Storage

The rising interest in using hydrogen as a fuel has increased the demand for composite pressure vessels that can safely store hydrogen at a working pressure of 70 MPa. However, a significant challenge to commercialization lies in developing optimized vessel designs that minimize both cost and weight. Analytical models have proven valuable for design optimization since they enable a quick analysis of a large number of options. Despite this, existing models fail to combine three aspects that are essential for a correct analysis of hydrogen pressure vessels: validity for asymmetric lay-ups, including out-of-plane stresses since these are thick-walled vessels, and predicting stress variations near the dome-cylinder interface. Therefore, this work presents a closed-form analytical model that integrates these three features through a superposition of two models. The model's accuracy is evaluated by comparing the results with finite element simulations, showing excellent agreement across the entire stress distribution.