In-plane permeability of sheared fabrics

Shear is the main mode of deformation in the draping of fabrics over comple x mould geometries in composites manufacturing. Hence, the measurement and prediction of the in-plane permeability of sheared fabrics is a crucial tas k for the design of resin transfer moulding and other composites processing techniques of complex shaped articles. A mathematical model has been devel oped and applied to predict the inplane permeability in the two principal d irections and the angle of the flow ellipse for sheared assemblies of bi-di rectional woven fabrics that are in-plane isotropic to flow when unsheared. Modelling was accompanied by in-plane permeability measurements for unshea red and sheared woven fabric assemblies, and a comparison of this experimen tal permeability data with the proposed model proved encouraging. A study i nto the change of the areal density of different woven fabrics with shear a ngle has also been included. (C) 2001 Elsevier Science Ltd. All rights rese rved.