Understanding buckling containment features for aerospace panel design

• Main Author: Houston, Graham James Leslie
• Published: Queen's University Belfast 2016
• Subjects: 629.1
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.706978

To improve aircraft structural performance requires practical design changes and better incorporation of advanced technologies. Instability failure modes typically constrain aerospace panel designs because buckling occurs at stresses less than that of material yield. Buckling containment features, small stiffeners located between the primary stiffeners/stringers, provide the ability to significantly improve panel-buckling stresses and thus exploit the full potential of available materials. Inclusion of buckling containment features into industrial panel sizing procedures is constrained by the current inability to robustly predict and understand the complex buckling behaviour. To aid inclusion requires a novel design approach that facilitates the extraction of understanding and selection of the optimum design. The project develops a finite element modelling methodology that permits robust buckling behaviour prediction of plates with buckling containment features. A novel design chart presents compression and shear loading buckling behaviour predictions that are applicable to both high load intensity wing and low load intensity fuselage applications. Interrogation of the design charts enhances current understanding of how plates with buckling containment features buckle. An experimental verification indicates the finite element modelling methodology to be accurate to within approximately 20% and 7% for initial and collapse buckling behaviour respectively. These deviations result from differences between the configuration of the finite element modelling methodology, the design of the test specimens, and the experimental setup. The work develops the first theoretical compression buckling framework for predicting PBCF buckling behaviour subject to compression loading. A verification process against predictions finite element analysis indicates a correlation error of less than 5% when considering structure of aspect ratio greater than three. Furthermore, using regression analysis and finite element analysis, the work develops a computationally efficient closed-form means to predict PBCF buckling behaviour that is suitable for inclusion into early (conceptual/preliminary) aerospace panel sizing procedures.