S. Jambu, PECHINEY Aviatube, Montreuil-Juigné, France; F. Eberl, Alcan Rhenalu, Issoire Cedex, France; F. Heymes, Alcan Aerospace, Issoire, France; K. Juhl, Airbus Germany, Bremen, Germany; J. J. Dittberner, Airbus Saint-Nazaire, Saint-Nazaire, France
After the successful introduction of 2024 high strength (2024HS) for fuselage frames in wide body aircraft such as the Airbus A380, even further weight gains in future aircraft programs are expected, thanks to advanced metallic extruded frames.
Depending on the mission and the geometry of the aircraft, a balance of manufacturing capability (forming), strength and fatigue performance has to be found:
- In wide body aircraft, a local smaller forming radius might be necessary due to the oval geometry of the fuselage.
- The permanent increase of the inspection intervals imposes higher fatigue performances.
- The use of higher strength alloys allows redistribution of the static load and optimization of the weight reduction performance.
Over the last several years, fuselage frames design and material have progressed. From 2024 bended sheets, extruded integral fames made of 2024 High Strength are now used on several aircraft. After a rough overview of the potential loading of fuselage frames, the requested properties will be examined and several material properties will be compared. Last generation Al-Li alloys as 2196 will be compared to today’s flying alloys such as 2024HS and other higher performance alloys out of 7xxx families for example. Material properties needed as strength, fatigue and corrosion performance will be evaluated after representative manufacturing schedules simulated on laboratory scale. Industrials trials have confirmed the excellent formability of 2196.
Summary: After the successful introduction of 2024 high strength (2024HS) for fuselage frames in wide body aircraft such as the Airbus A380, even further weight gains in future aircraft programs are expected, thanks to advanced metallic extruded frames.
Depending on the mission and the geometry of the aircraft, a balance of manufacturing capability (forming), strength and fatigue performance has to be found. In wide body aircraft, a local smaller forming radius might be necessary due to the oval geometry of the fuselage. The permanent increase of the inspection intervals imposes higher fatigue performances. The use of higher strength alloys allows redistribution of the static load and optimization of the weight reduction performance.
Over the last several years, fuselage frames design and material have progressed. From 2024 bended sheets, extruded integral fames made of 2024 High Strength are now used on several aircraft.
After a rough overview of the potential loading of fuselage frames, the requested properties will be examined and several material properties will be compared.
Last generation Al-Li alloys as 2196 will be compared to today’s flying alloys such as 2024HS and other higher performance alloys out of 7xxx families for example.
Material properties needed as strength, fatigue and corrosion performance will be evaluated after representative manufacturing schedules simulated on laboratory scale. Industrials trials have confirmed the excellent formability of 2196.
