Introduction to Aircraft Structural Analysis (Elsevier Aerospace Engineering)

23.3 Wing Ribs 629

Fig.23.12

Equilibrium of stiffener 56.

Fig.23.13

Equilibrium of the rib forward of stiffener 31.

Finally,weshallconsidertheribflangeloadsandthewebshearflowatasectionimmediatelyforward
ofstiffener31.FromFig.23.13,inwhichwetakemomentsaboutthepoint3,

M 3 =2[( 50000 + 95000 )×7.0− 95000 ×13.0]+ 15000 × 300 =4.06× 106 Nmm

Thehorizontalcomponentsoftheflangeloadsatthissectionarethen

Px,1=Px,3=

4.06× 106

300

=13533.3N

andtheverticalcomponentsare

Py,1=Py,3=3626.2N