Vibration Analysis of Composite Wing Structures by a Matrix Form Comprehensive Model

A dynamic model for stiffened composite multicell wing structures is developed. In this model, the extensional, bending,andcouplingstiffnessesarecalculated notonly from theproperties of thecomposite laminatesofthewing skinbutalso fromthestringersand spare anges,whicharetreatedase bersofapseudolamina.Thearrangementof the wing spar webs and ribs is then treated like a sandwich honeycomb core, from which an equivalent transverse shearmodulusofthewing structuresiscalculated. Withtheseestimated properties,thecompositewing structureis modeled, incorporating the effects of bending‐ torsion coupling, warping restraint, transverse shear deformation, shapeofairfoil,rotaryinertia,etc.Toavoidcomplexityofformulation,thematrixformrepresentationisintroduced, which then makes most of the equations forthe vibration analysisbearthesame form as thoseoftheclassical beam theory. Thus, by following the classical approach, the composite wing structures can be studied analytically. Nomenclature A = area Aij, Bij, Dij = extensional, coupling, and bending stiffness B f