Desempenho e segurança de cilindros de pressão Tipo 4 para armazenamento de hidrogênio: uma abordagem de simulação computacional

Abstract

Within the scope of the safety and performance of Type 4 pressure vessels for green hydrogen storage, the structural, thermal, modal, and fracture response was analyzed using computational simulation via ANSYS Workbench, based on the criteria of the ASME Section X, Appendix 8 standard. A cylinder composed of an HDPE liner, T700/Epoxy composite, and an Aluminum 6061 T6 boss (outer radius 150 mm, length 650 mm) was modeled using 1/8th symmetry. The analyses included: static structural simulation under 70 MPa internal pressure; steady-state thermal analysis with 85°C in-ternal and 28°C external temperatures; modal analysis for identifying natural frequenci-es; and fracture analysis involving the introduction of a 1 mm x 3 mm semi-elliptical crack in the composite. The structural analysis results indicated a maximum principal stress of 1630 MPa before the crack (exceeding the estimated allowable limit of ~991 MPa) and 1.397E4 MPa at the crack tip, with a maximum deformation of ~14 mm. The thermal analysis confirmed operation at the 85°C limit in the liner. The modal analysis identified the first 6 natural frequencies (between ~1083 Hz and ~2570 Hz), with slight alterations due to the crack. The fracture analysis resulted in maximum Stress Intensity Factors of KI ≈ 142 MPa√m, KII ≈ ±30 MPa√m, and KIII ≈ -46 MPa√m (absolute va-lue), indicating critical mixed-mode loading in the depth direction. Therefore, computa-tional simulation is demonstrated as an essential tool for assessing safety, identifying critical stress and temperature points near standard limits, and quantifying the signifi-cant impact of defects, highlighting the need for design optimization.