The development of a preliminary structural design optimization method of an aircraft wing-box skin-stringer panels

In the current paper a methodology for the design optimization of a skin-stringer panel of an aircraft wing-box is presented. The ability to resist the compressive load is assessed through a stability study to compute the critical buckling load of the stiffened panel while the ability to resist the tensile load is assessed through damage tolerance analysis of the lower wing panels. The design methodology of the compression panel included general and local failure modes as well as panel beam column analysis that are common in aerospace compression structures. Linear Elastic Fracture Mechanics theory is applied for the design of the tension panels where the Boundary Element Method is used to perform numerical crack growth analysis. Optimization routines have been developed and the design methodology is validated by comparison with several existing skin-stringer panels from four jet aircrafts and showed a good agreement. Finally, the developed design methodology has been used to design the skin-stringer panels of one complete bay in the wing-box of a DLR-F6 aircraft.