The postbuckling behavior of joined-wing configurations has not been fully addressed in the past. This topic is extensively discussed in this work. Starting from a baseline configuration, geometrical parameters as well as wings' load repartition are varied to assess their influence on buckling occurrence. The snap-buckling phenomenon and postcritical pattern are investigated with the adoption of the arc-length technique. The complex load transferring through the joint induces a deformation shape that can no longer carry additional load after a critical point is reached. An abrupt snap to a configuration that is not continuously adjacent to the previous one is then observed. Comparison with the instability state obtained via eigenvalue analysis demonstrates that buckling prediction through linear-buckling analysis is inadequate, and often, the actual critical load is overestimated. This study shows that, for PrandtlPlane joined-wing configurations, increasing the height-to-wingspan ratio is beneficial as far as structural response is concerned. This provides an important design guideline because it is well known from previous studies that high height-to-wingspan ratio decreases the induced drag and fuel consumption. The lift repartition and its effects on buckling show that an improvement of the structural stability of the joined-wing airplane can then be achieved by increasing the amount of aerodynamic load on the upper wing while reducing the lift on the lower wing. The strong bending-torsion coupling typical of highly swept joined wings and its influence on the postcritical response are also investigated and discussed.
Postcritical analysis of PrandtlPlane joined-wing configurations
Postkritische Analyse von verbundenen Flügelkonfigurationen (Prandtl-Flügel)
AIAA Journal ; 51 , 1 ; 161-177
2013
17 Seiten, 43 Bilder, 45 Quellen
Article (Journal)
English
Postcritical Analysis of PrandtlPlane Joined-Wing Configurations
Online Contents | 2013
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