The design principles of current and future metallic fuselage structures are presented after a brief review of the main regulatory requirements. Different designs are discussed jointly with current materials developments and relevant manufacturing technologies. A comparison of different designs is carried out focusing on the behavior of curved pressurized shells in the presence of large damages. The major advantages and disadvantages of these materials and technologies are reviewed and current challenges as well as current trends are presented. Fiber Metal Laminates (FMLs) is an extremely effective material-concept, for all structural areas dominated by fatigue and damage tolerance (FDT) requirements. In the A380 passenger aircraft, which entered service in 2007, Fiber metal laminates (Glare) have been extensively used m2) for the upper fuselage skin in combnation with bonded high strength stringers. To increase the material fracture toughness and static strength at the same time it is an extremely difficult undertaking since the two properties are mutually antagonistic. Promising materials to accomplish this challenge are the aluminum lithium alloys of the latest generation which are being developed in close cooperation with the material suppliers (Alcan and Alcoa). The new alloys have a lithium content less than 2 % to improve thermal stability, and copper in the range of 3% to keep high toughness levels. Crack propagation result shows that the artificial damage L2 was not propagating and several artificial cut were performed to accelerate the crack growth. Each small kink in the crack growth curve is the effect of an artificial cut. The slow crack growth is due to fiber bridging effect from the glass prepreg layers embedded in the skin. A natural crack extension occurred starting from a crack length of about 400 mm and after reaching the frames the propagation stopped again. A residual strength test was performed and the test reached an internal pressure of 1170 mbar. The crack turned and branched and was impossible to keep the internal pressure due to flapping.
Design of pressurized fuselage structures under consideration of damage tolerance requirements
2008
19 Seiten, 18 Bilder, 2 Tabellen, 5 Quellen
Aufsatz (Konferenz)
Englisch
Aspects of Damage Tolerance of Aircraft Fuselage Structures
British Library Conference Proceedings | 2008
|Aspects of damage tolerance of aircraft fuselage structures
Tema Archiv | 2008
|Damage Tolerance of Fuselage Dents
British Library Conference Proceedings | 2005
|On damage tolerance design of fuselage structure. Circumferential cracks
Tema Archiv | 1987
|