Three-dimensional thermomechanical analysis and performance assessment of an aluminum-lined, glass-fiber overwrapped hydrogen tank under hot-climate conditions

Hydrogen is increasingly central to decarbonizing transport and enabling long-duration energy storage, which places composite pressure vessels in harsh outdoor service. In sunbelt regions, tanks can face ambient temperatures approaching 50°C together with intense solar irradiation, producing through-thickness thermal gradients that elevate liner temperature, modify composite response, and, when combined with internal pressure and cycling, reduce fatigue safety margins. However, many existing design and assessment studies assume near-isothermal behavior or consider thermal effects in isolation, limiting quantitative guidance for hot-climate deployment. This work presents a fully coupled three-dimensional thermo-mechanical finite-element analysis of a Type-III hydrogen tank (aluminum liner with glass-fiber/epoxy overwrap) using COMSOL Multiphysics 6.3. The model couples heat transfer in solids and gas with structural mechanics and imposes external convection-radiation, peak solar irradiance, and ambient temperatures up to 50°C, together with internal hydrogen pressure and transient operating scenarios. Realistic solar exposure was achieved by computing the time-varying sun vector from the geographic coordinates of Maroua (Far North Cameroon) and applying it dynamically to the tank surfaces. Results showed pronounced vertical thermal stratification and crown-region heating, yielding an upper-dome thermal hotspot and circumferential stress bands peaking near 220 MPa (below liner yield), with predominantly radial displacements. Despite moderate stresses over most of the wall, fatigue damage localized near the lower outer shell/skirt junction, where geometric curvature and support constraints amplified the coupled thermo-mechanical stress range; the usage factor reached about 0.35 in this region while remaining below 0.1 elsewhere. Accordingly, the peak fatigue damage parameter increased from 0.291 under purely mechanical loading to approximately 0.35 ± 0.03 under coupled thermo-mechanical conditions. Importantly, this value represents the baseline environmental damage penalty per single 24-hour diurnal cycle rather than total cumulative lifetime damage, which will further accumulate under multi-cycle daily fast-refueling operations. To verify the framework’s numerical robustness against operational uncertainties, model credibility was evaluated through a reproducible measurement-emulation benchmark: synthetic sensor time series for crown gas temperature, maximum von Mises stress, and maximum displacement were generated by sampling the simulated signals and adding sensor-like noise and occasional outliers. The reconstructed signals showed the lowest estimation errors (highest precision) for temperature and displacement, whereas peak-stress maxima exhibited higher dispersion, consistent with the sensitivity of extremum metrics to boundary-condition and property uncertainties. The study identifies the lower shell/skirt junction as the primary life-limiting region during hot-day cycling and motivates targeted mitigations such as local geometry smoothing, overwrap reinforcement, and thermal management to improve durability in hot climates.