Page 475 - Aircraft Stuctures for Engineering Student

456 Structural constraint

Fig. 11.10 Six-boom beam subjected to a shear load.

is shared equally by the two webs. Also, since the beam has been idealized, the shear
flow at any section will be constant between the booms so that, for a web, the situa-
tion is that shown in the free body diagram of Fig. 1 1.1 1; in addition, the corner
booms are subjected to equal and opposite loads PB. The complementary shear
flows SJ2h are applied to the corner booms as shown so that the top cover, say, is
subjected to loads as shown in Fig. 11.12. We assume that suitable edge members
are present at the free end of the cover to equilibrate the shear flows; we also
assume that strains in the transverse direction are neghgible.
It is advantageous to adopt a methodical approach in the analysis. Thus, use may
be made of the symmetry of the cover so that only one edge boom, one panel and the

Fig. 11.1 1 Loads on webs and corner booms of the beam of Fig. 1 1.10.