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Defect formation during preforming of a bi-axial non-crimp fabric with a pillar stitch pattern

Chen, S.; McGregor, O.P.L.; Harper, L.T.; Endruweit, A.; Warrior, N.A.

Defect formation during preforming of a bi-axial non-crimp fabric with a pillar stitch pattern Thumbnail


S. Chen

O.P.L. McGregor

Associate Professor - Composites Manufacturing

Professor of Mechanical Engineering & Head of Research Division


To capture the asymmetrical shear behaviour of a bi-axial NCF with a pillar stitch, a non-orthogonal constitutive model was developed and implemented in finite element forming simulations. Preforming experiments indicate that the local distribution of defects is significantly different on both sides of each bi-axial ply, with two different defect mechanisms observed. Correlation with simulation results indicates that one defect type is caused by excessive shear, inducing out-of-plane wrinkling in regions of positive shear (macro-scale wrinkling). The other defect type is caused by fibre compression, inducing in-plane wrinkling in regions of negative shear (meso-scale wrinkling). Local distributions of shear angle and wrinkling strain were used to determine the wrinkling mode and to confirm the corresponding defect mechanism. Results indicate that simulations based on the advanced constitutive model can predict local shear angles within ±5°of experimental values and that predicted wrinkling positions and defect types correlate well with the experiments.

Journal Article Type Article
Acceptance Date Sep 24, 2016
Online Publication Date Sep 26, 2016
Publication Date 2016-12
Deposit Date Oct 13, 2016
Publicly Available Date Oct 13, 2016
Journal Composites Part A: Applied Science and Manufacturing
Print ISSN 1359-835X
Electronic ISSN 1359-835X
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 91
Pages 156-167
Keywords Fabrics/textiles; Defect; Finite element analysis (FEA); Forming; Preform
Public URL
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