Investigation of Saint Venant's Principle as Related to Laminated Composite Plates

The structural stiffness properties of composite laminated plates are experimental information needed in order to design aircraft components manufactured with composite materials. A common test used to obtain the necessary moduli is to apply a tension load on the ends of the specimen. Little study, if any, has been reported relating the application of the Saint Venant's principle within a multi-ply laminated plate. Previously, researchers have shown that routine application of Saint Venant's principle in problems involving a single composite lamina is not generally justified. This study offers justification for using Saint Venant's principle in commonly laid-up graphite epoxy plate specimens. The boundary conditions considered are attempts at modeling varying end supports for an in-plane loading. The analysis has been carried out using a finite element model considering three aspect ratios: 3, 5, and 10. (Author)