Periodic Reporting for period 2 - OASIS (Optimisation of Friction Stir Welding (FSW) and Laser Beam Welding (LBW) for assembly of structural aircraft parts)
Okres sprawozdawczy: 2019-05-01 do 2021-03-31
The achieved technical objectives of the project have advance three welding technologies (FSW, Friction Stir Spot Welding (FSSW) and LBW) for manufacturing complex lightweight aluminium structures. Inspection of the joints was be carried out in accordance with relevant aerospace standards, and an elaborate mechanical testing program has shown excellent mechanical properties for a range of alloys, joint configurations and welding processes. Upon completion of the projects, two full scale cargo door demonstrators were produced, one with friction stir welding processes and one with laser beam welding.
- The use of SSFSW (including corner welding) and RFSSW of stiffeners and frames to skins in a T-configuration, with material combination of AA2000 and AA7000 series alloys.
- The utilisation of the AA5xxx series alloy, specifically the AA5028 Al-Mg-Sc alloy, welded using LBW without a filler addition which would greatly simplify manufacturing.
- The use of SSFSW to weld curved panels in a butt-joint configuration.
- The implementation of numerical modelling to model the welding processes as their effects on structural integrity, distortion and residual stress for welded cargo doors.
- The implementation of a Digital Twin to accurately predict the associated costs for the rivetless assembly when fabricating using welding technologies.
Overall the developments have proven that by using welding techniques (FSW, FSSW and LBW), “leaner” parts can be used to fabricate aerostructures for fuselage applications, leading edge, wing panels, nacelles and doors. The light-weighting is achieved by eliminating rivets, sealant and flanges, reduced frame thickness, and the ability to have continuous joints, rather than spot joints. With the use of welding techniques to produce rivetless assemblies, joining time could be reduced, by 75%, than when using manual riveting.
The development of OASIS technologies, combined with other fuel consumption reduction steps and engine developments being undertaken in the JTI, will result in the existing fleet of civil aircraft being able to be replaced with more fuel efficient alternatives, and ultimately supporting the fabrication of a new generation of zero-emission aircraft in the next decade.