Introduction to Aircraft Structural Analysis (Elsevier Aerospace Engineering)

600 CHAPTER 22 Wings

22.6 TaperedWings........................................................................................

Wingsaregenerallytaperedinbothspanwiseandchordwisedirections.Theeffectsontheanalysisof
taperinasingle-cellbeamhavebeendiscussedinSection20.2.Inamulticellwingsection,theeffects
aredealtwithinanidenticalmannerexceptthatthemomentequation(20.16)becomes,foranN-cell
wingsection(seeFigs.20.5and22.8),

Sxη 0 −Syξ 0 =

∑N

R= 1

∮

R

qbp 0 ds+

∑N

R= 1

2 ARqs,0,R−

∑m

r= 1

Px,rηr+

∑m

r= 1

Py,rξr (22.13)

Example 22.4
A two-cell beam has singly symmetrical cross sections 1.2m apart and tapers symmetrically in the
ydirectionaboutalongitudinalaxis(Fig.22.12).Thebeamsupportsloadswhichproduceashearforce
Sy=10kNandabendingmomentMx=1.65kNmatthelargercrosssection;theshearloadisapplied
intheplaneoftheinternalsparweb.Ifbooms1and6lieinaplanewhichisparalleltotheyzplane,
calculatetheforcesintheboomsandtheshearflowdistributioninthewallsatthelargercrosssection.
Theboomsareassumedtoresistallthedirectstresses,whilethewallsareeffectiveonlyinshear.The

Fig.22.12

Tapered beam of Example 22.4.