J.P. Benthem

In the design of swept wings with ribs parallel to the direction of the free stream, wing panels occur in the shape of a parallelogram. In order to render the structure amenable to stress analysis it may be assumed that the panels carry shear stresses only along the edges of the panels. In this way the structure becomes finitely redundant. This familiar method is generally applied to unswept wings with satisfactory results. Using this method, stresses can be predicted at the root or at any other point of the structure where the stresses deviate from those obtained by ordinary engineering theories of bending and torsion. However, the wing panels should be as near rectangular shape as possible. The present paper shows that this method, if applied to wing panels of parallelogram shape, gives faulty results. Special methods have been developed to deal with panels of such shapes. The stress-strain relationship of the oblique plate field is not upset. The structure then consists of a great number of structural elements for which the state of stress is onedimensional (spar and rib flanges and ·webs) and of elements for which the state of stress is two-dimensional (oblique wing panels). These panels render the structure infinitely redundant. Oblique coordinates and principles of calculus of variation (minimum of potential energy and minimum of complementary energy) are introduced in order to obtain solutions. However, the application has to be appropriate to the type of structure. Numerical results are given for a five-cell swept box beam.

WGL-Tagung, Köln, 1960

Conference Paper

englisch

21,0 x 29,7 cm, 6 Seiten

Jahrbuch der Wissenschaftlichen Gesellschaft für Luftfahrt, 1960; S.337-342; 1960; Braunschweig : Vieweg

NA

Bestellbar

1961