• PrandtlPlane
• structural optimization
• wing box

The purpous of this thesis is to make a preliminary studies for a structural optimization on a PrandtlPlane wing box configuration. The 250-seats aircraft taken in account, called PrP250, came from previous studies and optimizations.
The material considered for the unconventional wing box configuration is the Aluminium Alloy 2024-T3, typical of aeronautical applications, chosen in such a way as to be able to make appropriate comparisons with the current aeronautical solutions.

Initialy the model has been changed in terms of constraints and load conditions. This was done in an attempt to pursue a more physical description and reduce the parasitic stresses. Stress and displacement differences between the old and the new model were then evaluated.
Given the parasitic high stress peaks observed, the candidate focused on the refined structural design of the inner front wing section up to the kink.
In particular several structural optimizations of the above mentioned wing section have been carried out considering three different load cases. First, a static limit load case, corresponding to a load factor of 2.5. Then, two potentially critical gust response loads have been selected from a gust response analysis. Further optimizations are carried out considering the three load cases, and effects of incorporating such gust loads in terms of weight penalties are assessed.