21st Congress of International Council of the Aeronautical Sciences, Melbourne, Australia, 13-18 September, 1998
Paper ICAS-98-7.7.2

A FINITE ELEMENT STUDY OF THE POST-BUCKLING BEHAVIOUR OF A FLAT STIFFENED PANEL

Lynch C. J., Sterling S. G.
The Queen's University of Belfast, United Kingdom

Keywords: finite element study, post-buckling behaviour, flat stiffened panel

Analytical methods currently used to determine the buckling/postbuckling behaviour of aircraft fuselage structures are based on empirical/semi-empirical data and are hence over-conservative. The finite element (FE) method has the potential to eliminate this conservatism. A finite element study of the buckling and postbuckling behaviour of a flat stiffened riveted panel subjected to uniform in-plane compression is presented. The element type and mesh density required to accurately predict the buckling mode is investigated. Various methods of modelling the skin/stringer interface are also investigated and the importance of correctly modelling the behaviour in this region highlighted. Results from the FE analyses are compared to both experimental data and theoretical predictions. Correlation between FE predictions and test data is seen to be very good, the FE buckling and failure loads being within 2.5% of the experimental values. The theoretical predictions are used to demonstrate the range of conservatism associated with current analytical techniques. Results indicate a possible weight reduction of 5-12% by employing the FE technique over conventional analytical methods.

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