Experimental investigation of the draping properties of reinforcement fabrics

The draping behaviour of some fabrics commonly used in resin-transfer moulding processes has been examined. The aim of the initial part of this study was to investigate test methods for determining shear properties. The bias extension and simple shear test methods were compared, and the effects of aspect ratio and boundary conditions were also examined. The results showed considerable differences when different test methods, aspect ratios and boundaries were used. A means of eliminating boundary-condition effects and obtaining a true stress/strain relationship is indicated. Investigation of yarn slippage was also one of the major concerns in this study. Yarn slippage was found to be affected by non-uniformity of deformation,, boundary conditions and differences in fabric materials. Tensile and out-of-plane bending tests were conducted. The shear and tensile stress/strain relationships were modelled. The test results also provide the thickness change during shear, unloading behaviour, bending rigidity and the effect of wet-out on the maximum shear angle. (C) 1998 Elsevier Science Ltd, All rights reserved.