Finite elements analysis of thermoplastic AFP cryogenic hydrogen tank structures

This thesis investigates the structural performance of composite materials with thermoplastic matrices for use in cylindrical tanks designed for liquid hydrogen storage under cryogenic conditions. A material property database at cryogenic temperatures is developed and implemented in ANSYS Workbench. The study systematically examines the influence of several design parameters, including composite wall thickness, matrix and fiber type, liner presence, and liner material. Among the materials evaluated, carbon fiber-reinforced PPS and PEEK exhibit the best performance, while glass fiber composites are less effective. While the incorporation of an HDPE liner reduces the IRF, greater reductions for a lower mass penalty are realised when using higher performance thermoplastics, particularly PEEK and PPS, as a liner material as well as composite matrix. The optimal configuration—a 9.6 mm linerless CFPPS tank—achieves the highest performance between the selected configurations. Although the modeling approach is intentionally simplified, the findings offer valuable insights for material selection and structural optimization. The study also identifies key areas for future work, including improved modeling fidelity and the exploration of additional materials and geometries.