Introduction to Aircraft Structural Analysis (Elsevier Aerospace Engineering)

Problems 557

Ans. Wall12,1.86N/mm;43,1.49N/mm;32,5.21N/mm;27,10.79N/mm;remainingdistributionfollows
fromsymmetry.122mmtotheleftoftheweb27.

Fig. P.19.2

P.19.3 FigureP.19.3showsthecrosssectionofasinglecell,thin-walledbeamwithahorizontalaxisofsymmetry.
ThedirectstressesarecarriedbytheboomsB 1 toB 4 ,whilethewallsareeffectiveonlyincarryingshearstresses.
Assuming that the basic theory of bending is applicable, calculate the position of the shear center S. The shear
modulusGisthesameforallwalls.
Cellarea=135000mm^2 .Boomareas:B 1 =B 4 =450mm^2 ,B 2 =B 3 =550mm^2.
Ans. 197.2mmfromverticalthroughbooms2and3.

Fig. P.19.3

Wall Length (mm) Thickness (mm)

12, 34 500 0.8

23 580 1.0

41 200 1.2

P.19.4 Findthepositionoftheshearcenteroftherectangularfour-boombeamsectionshowninFig.P.19.4.The
boomscarryonlydirectstresses,buttheskinisfullyeffectiveincarryingbothshearanddirectstress.Theareaof
eachboomis100mm^2.