To reduce the impact of the growing aviation industry on European citizens, there is the need to reduce emissions in all successive phases of an aircraft lifecycle. This demanding task established within the Strategic Research and Innovation Agenda (SRIA) of the Advisory Council for Aviation Research and Innovation in Europe (ACARE) can only be achieved by implementing innovative (green) technologies and corresponding methodologies and concepts.
One opportunity to address these challenges is the introduction of Additive Manufacturing (AM) technologies in all stages of an aircraft life cycle. The unique manufacturing process of AM enables new design methodologies for ultra-lightweight structures, flexible and resource-efficient production of highly complex and low volume parts, innovative and resource-efficient supply chains and logistic concepts for manufacturing, repair, spare-part production as well as recycling and disposal.
With the introduction of additively manufactured plastic parts Airbus has already achieved first benefits in spare part production, regarding resource efficiency and cost savings. Airbus predicts a weight reduction of over 1 ton per aircraft in the short term through the introduction of AM. To achieve these ambitious goals and tap even further potential, AM of aluminium and AM specific design-processes and methodologies as well as supply chains and logistics have to be developed.
In addition, AM technologies enable great weight saving potential for structural components and significant reduction of material waste during production. Studies of topology optimized and bionic lightweight structures in titanium show up to 40% weight reduction with production waste smaller than 10% of the initial material. With the introduction of high strength aluminium alloys even greater weight saving is possible (see Figure 1). The weight and waste reduction through the introduction of AM will significantly reduce CO2 and NOx emissions, as claimed by SRIA.
Figure 1: Weight saving potential through Additive Manufacturing and bionic lightweight design (feasibility study of Technical University of Hamburg and Airbus Operations).
Due to the new possibilities of AM and the weight saving potential of bionic design, Airbus identified topology optimized and bionic structures as one key enabler to create competitive air vehicles in the future and reach the goals set in SRIA. In addition to introducing optimized single components in the near future, Airbus already envisions creating entire airplanes based on concepts of biomimetics (see Figure 2), which could only be realized by utilization of Additive Manufacturing on a broad scale and promise a weight saving of up to 30%. Furthermore, the design freedom of AM can be used to optimize the functionalities of a part. Engine Manufacturers for example are implementing injection nozzles and turbine-blades, based on AM, which are significantly more efficient and durable, reducing emissions during aircraft operation.
Despite all the advantages, one major challenge of Additive Manufacturing is the time consuming and expensive design process for bionically optimized parts. In combination with the comparably expensive AM process, in many cases the high costs for development and manufacturing of bionically optimized parts prevent the application of AM, limiting the energy- and resource-efficiency of the aircraft.
To overcome these barriers and increase the applicability of AM for aircrafts, with the goal of reducing the environmental impact of an aircraft along the complete life-cycle, the BionicAircraft Project has the following objectives:
- Increasing resource efficiency during aircraft manufacturing, by enabling broad application of AM for aircraft production and enhancing the resource efficiency of the AM process.
- Reduction of emissions during aircraft operation due to weight reduction by implementation of high strengths biomimetic lightweight AM structures.
- Increase of resource efficiency in maintenance, repair, overhaul and retrofit due to development of innovative additive repair methods for highly complex biomimetic structures, as well as innovative AM supply chains and spare parts logistics.
- Reduction of emission for recycling and disposal due to development of recycling methods for AM parts.
Figure 2: Airbus Concept Plane (courtesey of Airbus S.A.S.).