Experimental and finite element draping simulation for non-crimp and twill fabrics

For low cost and high volume composite manufacture, Liquid Composite Moulding (LCM) techniques such as Resin Transfer Moulding (RTM) are of increasing industrial interest. These techniques involve draping of fabric reinforcement layers into a mould for subsequent resin transfer. For composite materials to compete with metals in low cost, high volume manufacture, valid simulation of this fabric draping is necessary to ascertain if a fabric can be draped without forming defects. Additional permeability and mechanical analysis is reliant upon accuracy in this initial simulation stage. Therefore, this study experimentally and numerically investigates the deformation mechanisms of a woven 2/2 twill fabric and Non-Crimp Fabric (NCF) with the aim of validating a draping simulation code. PAMFORM™ is used as the basis for this work. A material model included in the code is investigated for the 2/2 twill, while a new NCF material representation is proposed to account for additional through thickness stitching constraints. Draping trials over a double hemisphere mould are conducted for final validation of material data calibrated through an extensive testing programme. Both bias extension and picture frame tests are conducted to characterise the shear behaviour of each material