Thin-Walled Struct. 23, 339-350, 1995
M.A. Stiftinger, I.C. Skrna-Jakl and F.G. Rammerstorfer
Institute of Lightweight Structures and Aerospace
TU Wien, Vienna, Austria
Computational investigations of the buckling and postbuckling behaviour of a
stringer-stiffened composite wing torsion box employing the finite element
method are presented.
Perfect and imperfect configurations - considering geometrical imperfections
as well as initial stresses - are discussed.
Two different loadcases are investigated: pure axial loading and axial
loading with a superimposed constant torsion moment.
The buckling behaviour is determined by tracing the load-deflection curves
using Riks' pathfollowing method.
Additional investigations such as accompanying eigenvalue analyses and
first ply failure calculations are performed for the first loadcase.
Special attention is put on the modeling of the stiffened regions, where
eccentrically placed layers have to be taken into account due to the
bonding of the stiffeners to the inner surface of the box.
The results show interesting phenomena, such as additional buckling points
in the post-buckling region, which, however, can hardly be detected by
simply considering the load-axial displacement path.