Introduction to Aircraft Structural Analysis (Elsevier Aerospace Engineering)

22.8 Cutouts in Wings 605

giving

=23.5mm

22.8 CutoutsinWings.....................................................................................

Wings, as well as fuselages, have openings in their surfaces to accommodate undercarriages, engine
nacellesandweaponsinstallations,andsoforth.Inaddition,inspectionpanelsarerequiredatspecific
positionssothat,asforfuselages,theloadsinadjacentportionsofthewingstructurearemodified.
Initially we shall consider the case of a wing subjected to a pure torque in which one bay of
the wing has the skin on its undersurface removed. The method is best illustrated by a numerical
example.

Example 22.6
Thestructuralportionofawingconsistsofathree-bayrectangularsectionboxwhichmaybeassumed
tobefirmlyattachedatallpointsarounditsperipherytotheaircraftfuselageatitsinboardend.The
skinontheundersurfaceofthecentralbayhasbeenremoved,andthewingissubjectedtoatorqueof
10kNmatitstip(Fig.22.16).Calculatetheshearflowsintheskinpanelsandsparwebs,theloadsin
thecornerflanges,andtheforcesintheribsoneachsideofthecutout,assumingthatthesparflanges
carryallthedirectloads,whiletheskinpanelsandsparwebsareeffectiveonlyinshear.

Fig.22.16

Three-bay wing structure with cutout of Example 22.6.