624 CHAPTER 23 Fuselage Frames and Wing Ribs
Sofarwehavebeenconcernedwithweb/stiffenerarrangementsinwhichtheloadshavebeenapplied
intheplaneofthewebsothattwostiffenersaresufficienttoresistthecomponentsofaconcentrated
load.Frequently,loadshaveanout-of-planecomponent,inwhichcasethestructureshouldbearranged
sothattwowebsmeetatthepointofloadapplicationwithstiffenersalignedwiththethreecomponent
directions (Fig. 23.6). In some situations, it is not practicable to have two webs meeting at the point
ofloadapplicationsothatacomponentnormaltoawebexists.Ifthiscomponentissmall,itmaybe
resistedinbendingbyanin-planestiffener;otherwise,anadditionalmembermustbeprovidedspanning
betweenadjacentframesorribs,asshowninFig.23.7.Ingeneral,nonormalloadsshouldbeapplied
toanunsupportedwebnomatterhowsmalltheirmagnitude.
Fig.23.6
Structural arrangement for an out-of-plane load.
Fig.23.7
Support of load having a component normal to a web.