The MISSP project aims at proposing new manufacturing concepts for metallic aircraft cargo doors. The main objective of this project is the development of cheaper and greener structures as an alternative to CFRP doors but this approach is also applicable for any stiffened skin panel structure. This will be made possible by the use of advanced materials, manufacturing techniques and design concepts. Expensive and polluting chemical milling operations shall be replaced by flat mechanical machining, while multi-parts riveted components shall be replaced by more integrated structures reducing the number of parts and the time-consuming mechanical riveting assembly processes. To support the advanced manufacturing technologies proposed in this challenging project, use shall be made of numerical modelling that will help designing appropriated tools and optimizing process parameters to achieve high quality demonstrators that shall be delivered to the topic manager.
The project has been divided into the development of 3 potential manufacturing routes and is followed by a cost and performance analysis.
– The first work package focusses on the manufacturing of the external door skin with the aim of replacing the chemically milled pockets by mechanically machined ones. Both stretch-forming on tailored tool blocks and high energy hydroforming alternative will be investigated for alloy AA2024.
– In the second work package, stringers will be integrated onto the Al-Mg-Sc 5028 skin by FSW or LBW welding the components together as a flat assembly (2D) followed by creep forming to obtain a curved structure.
– Finally, the third package shall be dedicated to the manufacturing of an integral structure, from High Energy Hydroformed plate AA7050, drastically limiting the number of assembly operations. To this aim, an innovative solution is proposed: a thick plate will be deformed by high energy hydroforming and subsequently machined into the final cargo door integral structure.