Investigation into the effects of inter-ply sliding during double diaphragm forming for multi-layered biaxial non-crimp fabrics

The effect of inter-ply sliding was investigated for multi-ply Non-Crimp Fabric (NCF) preforms during the Double Diaphragm Forming (DDF) process. A Finite Element (FE) model employed to investigate influence ply layup sequence and coefficient friction between fabric-fabric fabric-diaphragm interfaces. Simulation results indicate that in-plane fibre compression, caused by dissimilar shear deformation adjacent plies, can lead out-of-plane wrinkles, where wrinkle length is a function relative angle at ply-ply contact interface. most severe wrinkles occurred when 45° biaxial NCF preform with pillar stitch primary yarns. second parametric study conducted incrementally reducing Experiments confirmed are sensitive resistance plies therefore lubricating fibres minimise wrinkling defects deformation.