Thin-Walled Struct. 23, 339-350, 1995


LARGE BUCKLING AND POSTBUCKLING INVESTIGATIONS
OF IMPERFECT CURVED STRINGER-STIFFENED SHELLS
Part B: COMPUTATIONAL INVESTIGATIONS

M.A. Stiftinger, I.C. Skrna-Jakl and F.G. Rammerstorfer

Institute of Lightweight Structures and Aerospace Engineering,
TU Wien, Vienna, Austria


Abstract - 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.


(hjb,960715)