PUNCH – Reproducible and sustainable flax-carbon hybrids for primary helicopter structures
In this project, a helicopter primary structure is manufactured using a flax-carbon hybrid construction method, which is optimally designed based on process characterization and simulation.
Project Partners
Invent GmbH, TUM - Lehrstuhl für Hubschraubertechnologie
Duration
01.01.2025 – 31.12.2027
Funding authority
Federal Ministry for Economic Affairs and Climate Action
Motivation
The PUNCH project aims to reduce the CO₂ footprint of aviation by replacing conventional carbon fiber structures with eco-efficient flax-carbon hybrids in primary structures. Comprehensive process characterization is carried out through compaction, permeability, and swelling to develop robust processability and reproducible manufacturing. This maximizes the bio-share and sustainability on the material side, while also meeting aviation-specific requirements for fatigue strength, nonlinearities, and safety. The project thus bridges fundamental process research and the production-oriented implementation of real helicopter components, exemplified by a tail boom extension.
Method
At the Chair of Carbon Composites, the focus is on the material-process interaction of the infusion process and the optimization of the process using simulations. A comprehensive characterization will experimentally investigate the compaction behavior, permeability, and swelling of flax, carbon, and hybrid layups. Furthermore, infusion tests using VARI and RTM will provide important data on fill level and fill time, as well as on porosity, fiber volume content, and ply thickness. This data will then be incorporated into compaction and fill simulations, enabling the identification of an optimized hybrid construction through an extended parameter variation of the layup. Finally, a demonstrator will be manufactured and tested at the project partner, and a sustainability assessment using an LCA will be conducted at the LCC.
Acknowledgement
The Chair of Carbon Composites would like to thank the Federal Ministry for Economic Affairs and Climate Action (BMWK) for funding within the framework of the LuFo VI-3 aeronautics research program (“PUNCH”, funding ID: 20Q2230).
Contact Persons
David Faron, M.Sc.; Dipl.-Ing. Thomas Wettemann