DAVID is a consortium project with a total of ten partners from industry and research, which was initiated by the IKV as a successor project to DELFIN - and for which the IKV is the consortium leader. The central objective is to achieve a CO2 saving of -21 % CO2-eq per container during production through resource efficiency and substitution. This is to be achieved through the application of new end-to-end digital design methods, in-line quality assurance measures and the use of new adapted material compositions and processing technologies.
The KickOff meeting started in an informal atmosphere with summer temperatures and bright evening sun with a joint barbecue at IKV. The following day, after a round of introductions and a tour of the technical centre, the individual working groups held intensive discussions on their respective objectives.
Lightweight pressure vessels are essential components in the deployment of CO2-neutral hydrogen-based propulsion systems in the transportation sector. While battery storage will continue to dominate the passenger car sector for the foreseeable future, hydrogen is now the preferred alternative to conventional fuels for heavy-duty vehicles such as trucks, buses, trains and marine applications. However, hydrogen must be stored at high pressures (350-700 barg) or low temperatures. Due to lightweight requirements, the use of carbon fibre reinforced plastics (CFRP) is the only attractive material for mobile applications.
Traditionally, these thick-walled structures are manufactured from thermoset systems using the wet winding process. However, the significantly higher material utilisation has a positive effect on the CO2 savings potential. The laminate structure of the composite winding is largely determined by the limits of the fibrr placement layup. Today, it is not possible to achieve complete uniformity of laminate stress and thus optimum material utilisation, which leads to oversizing and thus increased material usage. In addition, the effective properties of the component, aging, and loading are stochastic in nature, which also currently leads to significant oversizing. However, this oversizing can be reduced by developing and using in-line process monitoring to detect strength-reducing process deviations.
The technological objective of the current research project is to obtain a realistic description of the vessel materials and the entire system during manufacture and product lifecycle by means of integrated digitalisation and application-specific characterization and modeling. The interactions within the Machine-Process-Material-Morphology-Property relationship will be analysed experimentally and simulatively, and will be modeled with suitable methods and made usable for optimisations in the form of digital twins of the manufactured pressure vessels. Developing this understanding and mapping it in virtual methods is a key objective in order to significantly increase the degree of material utilisation and thus ensure CO2 savings through resource efficiency.
Furthermore, alternative materials such as pre-impregnated fibre tapes, so-called towpregs, are to be improved and implemented, which promises a high material saving potential. Particularly with regard to the materials used, a pronounced dependence of the mechanical properties on the hydrostatic pressure, the temperature and the physical load, such as the influence of the media, can be observed. These further influence the damage behavior. For this purpose, a test system will be developed within the research project, which allows the testing of materials under cyclic, dynamic triaxial loading with hydrogen as a pressure medium.
The research project (03LB3099A) is funded by the German Bundesministerium für Wirtschaft und Klimaschutz (BMWK) as part of the program "CO2 savings through resource efficiency and substitution" from the Technology Transfer Program Lightweight Construction (TTP LB). We would like to extend our thanks to all organizations mentioned. The joint project has ten partners from research and industry along the entire value chain of pressure vessel production and is being coordinated by the IKV Aachen.
- NPROXX Jülich GmbH
- Bundesanstalt für Materialforschung und -prüfung (BAM)
- FORM+TEST Seidner&Co. GmbH
- Elkamet Kunststofftechnik GmbH
- ISATEC GmbH
- Westlake Epoxy GmbH
- FORWARD ENGINEERING GmbH
- Teijin Carbon Europe GmbH
- Envalior GmbH
Contact for questions:
Hakan Çelik, M.Sc.