Introduction to Aircraft Structural Analysis (Elsevier Aerospace Engineering)

23.1 Principles of Stiffener/Web Construction 623

Fig.23.4

Load distributions in flanges of the beam of Example 23.1.

Fig.23.5

Load distributions in stiffeners of the beam of Example 23.1.

ThisapproachcannotbeusedinthebayCDHGexceptatthesectionCJG,sincetheaxialloadinthe
stiffenerJKintroducesanadditionalunknown.
TheaboveanalysisassumesthatthewebpanelsinbeamsofthetypeshowninFig.23.1resistpure
shearalongtheirboundaries.InChapter9,wesawthatthinwebsmaybuckleundertheactionofsuch
shearloads,producingtensionfieldstresseswhich,inturn,induceadditionalloadsinthestiffenersand
flangesofbeams.Thetensionfieldstressesmaybecalculatedseparatelybythemethodsdescribedin
Chapter9andthensuperimposedonthestressesdeterminedasdescribedabove.