LESSONS FROM APPLICATION OF EQUIVALENT PLATE STRUCTURAL MODELING TO AN HSCT WING

Equivalent plate wing models based on classical plate theory have been used for more than two decades as computationally efficient structura l approximations for airplane preliminary design. Prior publications d escribing these models indicate satisfactory correlation with the corr esponding finite element analysis and test results. In reality, a sati sfactory correlation is not possible for certain types of structural w ing concepts. The circumstances under which approximation by current w ing equivalent plate theory is adequate are studied in this article. A Boeing HSCT wing modei with low aspect ratio is used and correlations are shown for displacements, stresses, and natural frequencies and mo de shapes. It is shown that current equivalent plate models based on c lassical plate theory are only adequate for wings with high transverse shear stiffness. Results based on a new equivalent plate formulation that accounts for transverse wing shear flexibility support this concl usion.