Buckling analysis of geodesically stiffened composite panels with discrete stiffeners
Abstract
A computationally efficient analysis is developed to predict the buckling loads of geodesically stiffened composite panels with discrete plate-like stiffeners under in-plane loads. The procedure accounts for the contribution of the in-plane extensional and out-of-plane bending stiffnesses of the stiffeners through the use of a Lagrange multipliers technique in an energy method solution. The analysis is capable of predicting the buckling loads of grid-stiffened panels for a variety of stiffener aspect ratios and stiffener laminate stacking sequences. It can also be used to design panels with variable density grid stiffeners across the panel width. Results of the proposed analysis showed that the buckling loads of geodesically stiffened panels are predicted more accurately, especially in the case of panels with shallow stiffeners, compared to an earlier analysis that assumes the stiffeners to be beam-like components. For plate-like stiffeners, laminate stacking sequence of the stiffeners is found to have a substantial effect on the critical load of a panel. It was demonstrated that the optimal stiffener is not always unidirectional, and tailoring the stiffener ply sequence can lead to improvement in panel stability. It was also shown that panels with a variable grid density can lead to designs with improved buckling performance compared to uniform density panels.
- Publication:
-
Journal of Aircraft
- Pub Date:
- September 1994
- Bibcode:
- 1994JAir...31.1197G
- Keywords:
-
- Buckling;
- Composite Structures;
- Energy Methods;
- Lagrange Multipliers;
- Laminates;
- Panels;
- Ply Orientation;
- Structural Stability;
- Aspect Ratio;
- Bending;
- Critical Loading;
- Loads (Forces);
- Structural Design;
- Structural Mechanics