Multimaterial airframes based on 3D joints between AM metals and carbon-fiber composites

The aim of MIMOSA Project is the development of joined multi-material structures with new concepts able to exploit the digital and hybrid processes in order to achieve higher technological and economic performances with respect to current traditional joints.

Furthermore, MIMOSA will lead to the application of circularity of materials and production by integrating the recycling, starting from the ideation phase of product and business.

These ambitions and associated needs will be achieved with innovative technology and competitive process for multi-material joints between AlSi10Mg alloy for additive manufacturing (AM) and composites (CFRP, carbon fiber-reinforced polymers).

The project proposes new joint concept design, after-service materials regeneration (50% of metals and 90% of CFRP), weight (-51%) and lead time (-65%) reduction and overall process environmental footprint reduction. A prototype of vertical stabilizer (VS) structure will be fabricated and analyzed as the business case of the Project.

At the end of the Project, TRL6 is expected by starting at TRL3. Many aerostructures are composed of CFRP skin and metal parts coupled by rivets.

However this kind of joint shows some drawbacks: (1) long time for assembling, (2) loss of fibers integrity due to rivet holes, (3) rivets payload, (4) joint surfaces treatment with paints needed, (5) rivets failure issues, (6) hard inspection and maintenance of rivets.

MIMOSA Project will go beyond the state of the art in building aircraft structures by providing: (1) scientific research-driven integration of different design fields and fabrication processes, (2) new AM-CFRP multi-material joint concept, (3) reduced waste of materials thanks to recycling and associated economic value generation, (4) enhancement of process performances of energy consumption, lead-time and cost, (5) fabrication of a vertical stabilizer prototype (OB4) for narrow body airliners with the new AM-CFRP joint as business case.