Development and assessment of a lightweight type III COPV for high-pressure helium storage in flight systems

Kurzfassung

This paper presents a comprehensive design and structural assessment methodology for a Type III composite overwrapped pressure vessel (COPV) developed for high-pressure helium storage in flight applications within the framework of the DLR ATHEAt project. The vessel, manufactured through filament winding, consists of an aluminum 5083-O liner and a carbon fiber–reinforced polymer (CFRP) T700SC/LY556 overwrap. The sizing process addresses the specific requirements for flight use—including weight optimization, flight hardware safety factors, and robustness under combined thermo-mechanical loading conditions. The sizing methodology is divided into two main steps: (i) automated optimization of the composite layup based on a linear axisymmetric static analysis to meet target burst and proof pressures, and (ii) detailed nonlinear finite element assessment accounting for liner plasticity and the interaction between the metallic and composite layers. Key parameters investigated include the geometric details of the liner and boss region, material properties over a temperature range, and the definition of safety margins for critical failure modes. The results demonstrate that the proposed approach yields a structurally efficient configuration that satisfies flight-relevant design constraints while maintaining adequate safety margins against liner yielding and fiber rupture. The findings support the ongoing efforts of the ATHEAt project to research new technologies for reusable space transportation systems and to develop lightweight, high-pressure composite storage solutions.