Modelling drape, stress and impact behaviour of non-crimp fabric composites

Abstract

Abstract: Each layer of non-crimp fabric (NCF) in a blanket has fibres that are essentially straight with a distinct orientation and uniform thickness. Consequently, for analysis purposes, each layer may be treated as an individual ply in classical laminate theory (Jones and Pickett, 2005). Similarly, it is reasonable to apply the same assumptions to a finite element (FE) analysis and most work to date has treated each layer as a quasi-unidirectional ply. However, some provisos need to be considered. First, bi-axial NCFs are commonly used for complex doubly curved geometries and can be required to undergo considerable drape deformation. This draping will deform fabric architecture changing properties such as infusion permeability and mechanical stiffness. Characterisation of mechanical properties for deformed NCF is a topic of current research; see for example Crooktson, Long and Jones (2002) for elastic properties, Greve and Pickett (2006) for failure, and Chapter 11 for mesoscopic analysis of deformed NCF. FE analysis of NCF covers a wide range of applications including draping, resin infusion, residual stress, static stress and impact analysis, amongst others. A brief review of relevant FE methods is first given, followed by their application to drape, infusion and stress/impact analysis, with some examples.