Effects of fibre architecture on deformation during preform manufacture

Abstract

Simulations of fabric deformation during preform manufacture are usually based on a kinematic mapping of the fibres onto the component. Whilst this approach can anticipate excessive deformation, it takes no account of the effect of fabric construction on subsequent forming characteristics. The aim of this study is to establish a relationship between fibre architecture and formability, and to incorporate this within an enhanced draping simulation. The approach utilises a geometric model for woven or warp- knitted fabrics, which forms the basis of a mechanical model for fabric deformation. The model is then used to determine the shear strain energy required to produce a particular draped fibre pattern. This is implemented within an iterative procedure to determine the draped pattern resulting in minimum strain energy. The results compare favourably with experiments for hemispherical preforms, where initial fabric construction is shown to have a significant effect on the resulting fibre orientations.