Non-linear finite element modelling of an integrally stiffened composite panel

Abstract

The progressive introduction of advanced fibre composite materials into aerospace structures has enabled significant performance improvements to be achieved. Structures using these materials are generally designed so that their behaviour is essentially linearly elastic through to failure. The realisation of further significant weight reductions in light-weight aerospace structures is highly dependent on design technologies which will enable postbuckling stiffened panels to be utilised in primary structures. The capabilities of the finite element code, MSC/NASTRAN, to predict the onset of buckling and subsequent postbuckling behaviour of a blade-stiffened fibre composite panel have been investigated. The panel consists of T300/914 carbon/epoxy unidirectional tape and is reinforced by integral stiffeners. Basic modelling techniques for the efficient analysis of such postbuckling assemblies are presented. It is concluded that the prediction of their performance requires specialist modelling skills and a sound understanding of the behaviour of the composite materials used in the structure.