davparlr
Senior Master Sergeant
A stffer wing will flex less but also have a higher natural frequency - the latter, when approximating the frequency of say a prop/engine combination or turbine blade rpms, could cause resonance, fatigue - and ultimately structural failure - (i.e. Comet)
Small point of clarification. While the Comet did have a problem with fatigue, it was not the wing flex. The issue was with the pressurization and depressurization cycling of the fuselage, a relatively new design feature after WWII. This pressure cycling caused fatigue failure around the rectangular windows among other places.
Fighter aircraft, with their rather short, strong wings probably have an insignificant flex.
Interesting note. The B-2 bomber, even with much fuel in the wings has almost no wing flex. The wing is 100% composite and composite material does not like to move in that direction. The composite wings are extremely strong.