Introduction to Aircraft Structural Analysis (Elsevier Aerospace Engineering)

Problems 473

Fig. P.15.3

ThewallthicknesstcanbetakenasverysmallincomparisonwithdincalculatingthesectionalpropertiesIxx,
Ixy,andsoon.

Ans. σz,1(midpoint)=−0.05Wl/td^2 , σz,1(built-inend)=−1.85Wl/td^2

σz,2(midpoint)=−0.63Wl/td^2 , σz,2(built-inend)=0.1Wl/td^2.

Fig. P.15.4

P.15.5 Athin-walledbeamhasthecrosssectionshowninFig.P.15.5.Ifthebeamissubjectedtoabendingmoment
Mxintheplaneoftheweb23,calculateandsketchthedistributionofdirectstressinthebeamcrosssection.

Ans. At1,0.92Mx/th^2 ;At2,−0.65Mx/th^2 ; At3,0.65Mx/th^2 ;

At4,−0.135Mx/th^2

P.15.6 The thin-walled beam section shown in Fig. P.15.6 is subjected to a bending momentMxappliedina
negativesense.Findthepositionoftheneutralaxisandthemaximumdirectstressinthesection.

Ans. NAinclinedat40.9◦toCx.±0.74Mx/ta^2 at1and2,respectively.