Stelia Aerospace has developed a full-scale thermoplastic fuselage demonstrator to allow an internal evaluation of the use of high performance thermoplastics – as opposed to thermosets – within a next generation single aisle aircraft. The demonstrator featured all the typical characteristics of a primary fuselage airframe those being thin skin, lightning protection, stringers and frames, to allow a detailed evaluation of these technologies in a true industrial environment.
Stelia Aerospace has invested several millions in their Arches Box TP Research & Technology project (2015-2017) within the CORAC (French Strategic Advisory Board for Civil Aviation Research) platform. The project is both a technological challenge, thanks to the much lower level of maturity than thermoset matrix composite, and an economic issue, because its global application for the fuselage of the single aisle aircraft (with demanding low cost – high rate requirements) must be more cost competitive than the previous generation metallic technologies.
As both the project owner and design authority, Stelia Aerospace manufactured the demonstrator skin with Automatic Fibre Placement (AFP - using thermoplastic slit carbon tapes and lightning strike protection) and Out of Autoclave (OOA) consolidation, before completing the final structure assembly at its in-house R & T centre Stelialab in Méaulte.
Stelia Aerospace has selected leading French suppliers in thermoplastic composites to provide complementary technology packages such as: dynamic robotic induction welding of TP stringers, fast stamping of stringers and frames and hybrid TP structures by over‐moulding short fibre and long fibre.
For the Arches Box TP project, Porcher’s Industries technical team developed an organosheet from the Pipreg range of thermoplastic solutions as the optimal material for the frames based on the initial Stelia Aerospace specification.
The PEKK based Pipreg laminates, supplied use a specific carbon reinforcement, providing an exceptional combination of mechanical and fatigue properties from cryogenic to very high temperatures. Thanks to a cutting-edge and disruptive development mixing chemistry and processing, Porcher Industries has been able to develop an improved interface between fibres and PEKK.
Porcher Pipreg laminates satisfied all testing, engineering and processing targets for the Arches Box TP project and were used by Stelia Aerospace to produce all composite frames in the demonstrator module, as well as being incorporated into an overmoulded access door component.
