Uncertainties due to Modeling Simplifications

A series of comparing analyses is carried out to estimate the influence of geometrical details on the accuracy of wing structural response. Global deviation parameters presented in section 1.2 are used to evaluate at first the change in structural stiffness components due to modeling approximations and secondly the influence of these alterations on the static deformation of the wing in flight direction considering the elastic angle of attack ael. For selected cases a static aeroelastic analysis is carried out to calculate the deviation of equilibrium state angle of attack and, therefore, to estimate the impact of altered structural stiffness on the aeroelastic response. To

stiffeners: rod elements

spars

stiffeners smeared

skin-stringer-

panels

Fig. 2 Components of the wing box structure

distinguish the deviations of structural stiffness five integral parameters are listed in tables 3 and 4 for each modeling effect. These parameters are the integral deviation of bending and torsional angles [Aw’} and [AQ] relative to the elastic axis of the wing, the "transformed" values [Aw’}tr and [AQ]tr of both angles in flight direction as well as the global deviation of elastic angle of attack, [Aael}.