Introduction to Aircraft Structural Analysis (Elsevier Aerospace Engineering)

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16.2 Shear of Open Section Beams 487

Fig.16.8


Shear center position for type of open section beam shown.


Fig.16.9


Determination of shear center position of channel section of Example 16.2.


TheshearcenterSliesonthehorizontalaxisofsymmetryatsomedistanceξS,say,fromtheweb.
IfweapplyanarbitraryshearloadSythroughtheshearcenter,thentheshearflowdistributionisgiven
byEq.(16.14)andthemomentaboutanypointinthecrosssectionproducedbytheseshearflowsis
equivalenttothemomentoftheappliedshearload.Syappearsonbothsidesoftheresultingequation
andmaythereforebeeliminatedtoleaveξS.
Forthechannelsection,CxisanaxisofsymmetrysothatIxy=0.AlsoSx=0andthereforeEq.(16.14)
simplifiesto


qs=−

Sy
Ixx

∫s

0

tyds (i)

where


Ixx= 2 bt

(

h
2

) 2

+

th^3
12

=

h^3 t
12

(

1 +

6 b
h

)
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