Multiple ply preforming of non-crimp fabrics with distributed magnetic clamping

A major barrier to high-rate manufacture of non-crimp fabric (NCF) preforms is the relatively low volume of research evaluating multiple ply forming strategies. This study presents an extension to the distributed magnetic clamping (DIMAC) method towards establishing flexible process control measures for multiple ply forming. A measure of wrinkling was devised to allow comparison across different stack thicknesses and the distributions of wrinkles were shown to correlate with process parameters in an experimental parametric study. Further, ply-bending mechanics were shown to have a dominant effect on the draw-in of compression folds, particularly when increasing the number of equivalent biaxial plies. However, by deploying targeted distributed clamps, three-ply, single-stroke strategies over a complex positive curvature geometry became viable. DIMAC is shown to facilitate the local adjustment of boundary conditions whilst offering flexibility in improving component quality.