Introduction to Aircraft Structural Analysis (Elsevier Aerospace Engineering)

19.3 Effect of Idealization on the Analysis 547

Fig.19.9

Curved web with constant shear flow.

or

Sx=q 12

∫^2

1

cosφds

which,fromFig.19.9,maybewrittenas

Sx=q 12

∫^2

1

dx=q 12 (x 2 −x 1 ) (19.7)

Similarly,theresultantofq 12 paralleltotheyaxisis

Sy=q 12 (y 2 −y 1 ) (19.8)

Thus, the resultant, in a given direction, of a constant shear flow acting on a web is the value of the
shearflowmultipliedbytheprojectiononthatdirectionoftheweb.
TheresultantshearforceSonthewebofFig.19.9is

S=

√

S^2 x+S^2 y=q 12

√

(x 2 −x 1 )^2 +(y 2 −y 1 )^2

thatis,

S=q 12 L 12 (19.9)