Periodic Reporting for period 1 - SUSTAINair (SUSTAINablility increase of lightweight, multifunctional and intelligent airframe and engine parts)
Okres sprawozdawczy: 2021-01-01 do 2022-06-30
Commercial aviation contributes 3.6% of global GDP and supports more than 65 million jobs. However, aviation also contributes 2-3% of the world’s manmade emissions of CO2 with transportation as a whole producing ~24% according to the UN Intergovernmental Panel on Climate Change (IPCC). SUSTAINair is thus dedicated to improving the environmental impacts caused by an aircraft throughout its entire life cycle.
SUSTAINair is taking up the challenge to foster innovation related to cost-competitive aviation products and services, while focusing on Circular Economy by researching on application of recycled materials and optimized resource recovery. The project investigates novel assembly/de-assembly/repair/reuse of parts/subassemblies by intelligent combinations of modern joining and innovative materials technologies. Furthermore, the project aims at a sustainable material usage by increasing the operational lifetime of structural components as well as reducing operational costs.
SUSTAINair is addressing the major challenge of GREENING OF AIRCRAFT – in a way, that environmental benefits are meeting economic viability and European competitiveness at once. It is focusing on two of the biggest levers to reduce energy consumption during flight operations: reduced masses and increased aerodynamic efficiency.
A large scale of synergies allows the consortium to focus on eight Key Enabling Technologies (KETs), each of which is targeting challenging Key Performance Indicators (KPIs). Validation of these KPIs will be performed individually per KET, but also in an integral manner by means of two demonstrators, reflecting the multi-material design philosophy, in which combinations of aluminium, titanium and FRP grades are used.
SUSTAINair’s R&D is organized through five Specific Objectives, each implemented by a dedicated technical work package. The two demonstrators will be manufactured and analyzed in WP5, including main features of all former WP1-4 and the respective KETs, and will lead to a broad range of Key Exploitable Results.
SUSTAINair is taking up the challenge to foster innovation related to cost-competitive aviation products and services, while focusing on Circular Economy by researching on application of recycled materials and optimized resource recovery. The project investigates novel assembly/de-assembly/repair/reuse of parts/subassemblies by intelligent combinations of modern joining and innovative materials technologies. Furthermore, the project aims at a sustainable material usage by increasing the operational lifetime of structural components as well as reducing operational costs.
SUSTAINair is addressing the major challenge of GREENING OF AIRCRAFT – in a way, that environmental benefits are meeting economic viability and European competitiveness at once. It is focusing on two of the biggest levers to reduce energy consumption during flight operations: reduced masses and increased aerodynamic efficiency.
A large scale of synergies allows the consortium to focus on eight Key Enabling Technologies (KETs), each of which is targeting challenging Key Performance Indicators (KPIs). Validation of these KPIs will be performed individually per KET, but also in an integral manner by means of two demonstrators, reflecting the multi-material design philosophy, in which combinations of aluminium, titanium and FRP grades are used.
SUSTAINair’s R&D is organized through five Specific Objectives, each implemented by a dedicated technical work package. The two demonstrators will be manufactured and analyzed in WP5, including main features of all former WP1-4 and the respective KETs, and will lead to a broad range of Key Exploitable Results.
Work covered in the P1 period was centred around progressing the individual material technologies in combination with advancing processing routes to enable the projected recycling scenarios.
The basis for this was a diligent definition and supervision of mechanical testing scenarios and general design requirements for all material categories (1st and 2nd life, similar and dissimilar joints) concluded in WP1, to accord their respective potential in future aircraft applications.
Intensive work was carried out on developing future cast and wrought aluminium alloys with enhanced recyclability. Wide ranges of intrinsic nanoeutectic as-cast alloys based on the Al-Mg-Si system (representing one of the dominant material streams in aluminium worldwide) were screened both by CALPHAD simulation and experimentally. Both lab-scale casting and industrial scale high pressure die casting were applied, with equivalent material properties in both. Likewise, a first generation of performance-enhanced Al-Mg-Si (6xxx) wrought alloys was produced and characterized.
Additive manufacturing of Titanium powders (Ti64) was performed using both virgin and recycled powder feedstock. By scanning multiple parameter configurations of LPBF manufacturing, first correlations between feedstock “age” and material performance could be obtained.
CFRP upcycling development was performed both for thermoset and thermoplastic secondary resources. By developing and testing two variants of moulds for thermally assisted pressing, a variety of recyclate grades from real production wastes (e.g. from milling or chopping) were investigated for both material categories.
First joining trials have been performed, for both metal as well as thermoplastic and thermoset composites. Titanium samples with additively manufactured pins have been joined with thermoset composite sheets and single lap shear (SLS) tests have been performed. For the metal and thermoset composite parts, both 1st and 2nd life materials have been considered and a variety of process parameters screened.
To work towards next-generation health management and monitoring systems, not only damage modes and damage propagation were analysed, but also novel sensors and their structural integration progressed beyond state of the art. In addition, potential SHM methods and system designs were reviewed, selected, further developed, and numerically and experimentally validated on SLS specimens on component level.
Due to unforeseeable bankruptcy of partner Aerocircular during this period, the original plan to provide beyond lab-scale proof of feasibility of the “automated rivet removal robot head” had to be restructured. Therefore, an equivalent approach was defined relying on water jet cutting. The anticipated TRL level had to be reduced to actual lab-scale trials which will be performed from period P2 onwards. Further adding the new project partner AELS, a professional aircraft dismantling company, enables to provide equivalent impact to sustainable aerospace dismantling.
The basis for this was a diligent definition and supervision of mechanical testing scenarios and general design requirements for all material categories (1st and 2nd life, similar and dissimilar joints) concluded in WP1, to accord their respective potential in future aircraft applications.
Intensive work was carried out on developing future cast and wrought aluminium alloys with enhanced recyclability. Wide ranges of intrinsic nanoeutectic as-cast alloys based on the Al-Mg-Si system (representing one of the dominant material streams in aluminium worldwide) were screened both by CALPHAD simulation and experimentally. Both lab-scale casting and industrial scale high pressure die casting were applied, with equivalent material properties in both. Likewise, a first generation of performance-enhanced Al-Mg-Si (6xxx) wrought alloys was produced and characterized.
Additive manufacturing of Titanium powders (Ti64) was performed using both virgin and recycled powder feedstock. By scanning multiple parameter configurations of LPBF manufacturing, first correlations between feedstock “age” and material performance could be obtained.
CFRP upcycling development was performed both for thermoset and thermoplastic secondary resources. By developing and testing two variants of moulds for thermally assisted pressing, a variety of recyclate grades from real production wastes (e.g. from milling or chopping) were investigated for both material categories.
First joining trials have been performed, for both metal as well as thermoplastic and thermoset composites. Titanium samples with additively manufactured pins have been joined with thermoset composite sheets and single lap shear (SLS) tests have been performed. For the metal and thermoset composite parts, both 1st and 2nd life materials have been considered and a variety of process parameters screened.
To work towards next-generation health management and monitoring systems, not only damage modes and damage propagation were analysed, but also novel sensors and their structural integration progressed beyond state of the art. In addition, potential SHM methods and system designs were reviewed, selected, further developed, and numerically and experimentally validated on SLS specimens on component level.
Due to unforeseeable bankruptcy of partner Aerocircular during this period, the original plan to provide beyond lab-scale proof of feasibility of the “automated rivet removal robot head” had to be restructured. Therefore, an equivalent approach was defined relying on water jet cutting. The anticipated TRL level had to be reduced to actual lab-scale trials which will be performed from period P2 onwards. Further adding the new project partner AELS, a professional aircraft dismantling company, enables to provide equivalent impact to sustainable aerospace dismantling.
A nanoeutectic alloy was derived from compositions of arbitrarily selected EoL aircraft structures enhanced by modest tuning of alloying elements. If properly chosen, nanostructuring offers huge potential both with respect to achievable mechanical performance as well as upcycling potential by tolerating impurity contents increased by up to one order of magnitude. Expanding this universal approach to more/other dominant impurity elements (e.g. copper and zinc being the most relevant in aeronautics) that hinder upcycling of real waste streams today, the scope of the concept goes way beyond “mere” aerospace grade materials but could open a universal path to extracting higher performance components from universal aluminium-waste streams. A broad range of such alloys can significantly reduce Europe’s dependency on non-domestic primary Al resources, next to offering a three to fivefold direct reduction in processing energy consumption.
Failure modes in recycled, hence by definition short fibre CFRP-materials impose unprecedented challenges towards robust design of such structures. By simultaneously advancing production routes and applying advanced characterization of failure in this materials, robust processing windows become available, elucidating the performance limits of fully recycled fibre reinforced materials. To enable the integral design of subassemblies in line with circular economy concepts, the focus of SUSTAINair is on welding and bonding techniques, thus replacing rivets at maximum. As could be proven on microstructural scale, e.g. nanostructured eutectic aluminium alloys show no weakening of joining interfaces. Structural assemblies that are to date milled from large precursors at immense material losses can be designed and produced by combining near net-shape at equal performance. Choosing the same base of alloys (Al-Mg-Si) for both cast and wrought substructures puts omitting rivets overall within reach in future generation aircraft.
Next to advancing SHM and MRO methodology for all material classes described, realizing novel sensor generations that can be integrated into assemblies without reducing cyclability of structures in EoL will allow to reduce safety margins (in particular with respect to secondary feedstock utilization) in product/structural design without compromising safety.
Failure modes in recycled, hence by definition short fibre CFRP-materials impose unprecedented challenges towards robust design of such structures. By simultaneously advancing production routes and applying advanced characterization of failure in this materials, robust processing windows become available, elucidating the performance limits of fully recycled fibre reinforced materials. To enable the integral design of subassemblies in line with circular economy concepts, the focus of SUSTAINair is on welding and bonding techniques, thus replacing rivets at maximum. As could be proven on microstructural scale, e.g. nanostructured eutectic aluminium alloys show no weakening of joining interfaces. Structural assemblies that are to date milled from large precursors at immense material losses can be designed and produced by combining near net-shape at equal performance. Choosing the same base of alloys (Al-Mg-Si) for both cast and wrought substructures puts omitting rivets overall within reach in future generation aircraft.
Next to advancing SHM and MRO methodology for all material classes described, realizing novel sensor generations that can be integrated into assemblies without reducing cyclability of structures in EoL will allow to reduce safety margins (in particular with respect to secondary feedstock utilization) in product/structural design without compromising safety.