Shape distortions in composites forming
12th of mei 2005
Part of the project related to the thermosetting matrix was performed within the framework of Brite Euram project ‘Precimould’. The part related to rubber pressing was performed with Stork Fokker and Ten Cate Advanced Composites within the project ‘Precision Rubber Pressing’ sponsored by the Netherlands agency for aerospace programmes NIVR.
The goal of the research described in this thesis was to develop a numerical design tool for high-precision composites forming. An efficient FE model which predicts process-induced shape distortions is developed, enabling correction of the tools beforehand. The primary distortional factors are identified and evaluated for different forming process.
An efficient simulation strategy is discussed, taking into account the primary distortional factors. A multi-layer element is proposed, which is able to describe interlaminar shear induced by tool contact. Layer-wise stresses are calculated without the cost of solving the degrees of freedom of separate fabric layers. The composite forming process is subdivided into separate steps, which enables the design of a different solution strategy for each step. The solution strategy is recognised as a promising tool for simulations of shape distortions in composite forming in the near future.
figure 1: Vertical disp. (mm) caused by spring forward
figure 2: Microscopic picture of an edge of a rubber pressed specimen.
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S. Wijskamp, E.A.D. Lamers & R. Akkerman, Spring-forward of woven fabric reinforced composites, in: Proceedings of TexComp 5, the 5th International Conference on Textile Composites, 18-20 September (2000), Leuven, Belgium.
E.A.D. Lamers, S. Wijskamp & R. Akkerman, Modelling the thermo-elastic properties of skewed woven fabric reinforced composites, ECCM 9 (2000), Brighton, UK.
S. Wijskamp, E.A.D. Lamers & R. Akkerman, Effects of out-of-plane properties on distortions of composite panels,in: Proceedings of Fibre Reinforced Composites 2000, editor A.G. Gibson,Woodhead Publishing Ltd.,2000 p.361-368.
E.A.D. Lamers, R. Akkerman & S. Wijskamp, Drape Modelling of Multilayer Fabric Reinforced Thermoplastic Laminates, Texcomp-6 conference Philadelphia(PA), 2002.
E.A.D. Lamers, R. Akkerman & S. Wijskamp, Orientation Modelling for Rubber Press Forming of Thermoplastic Laminates, International Journal of Forming Processes, 2002, p.443-463.
E.A.D. Lamers, R. Akkerman & S. Wijskamp, Fibre Orientation Modelling for Rubber Press Forming of Thermoplastic Laminates, 5th ESAFORM conference Krakow (Poland),2002 , p.323-326.
S. Wijskamp, E.A.D. Lamers, R. Akkerman & E.C. van de Ven, Warpage of rubber pressed composites, ECCM 10, Brugge (Belgium), 2002.
S. Wijskamp, E.A.D. Lamers & R. Akkerman, Residual stresses in rubber formed thermoplastic composites, 6th ESAFORM conference, Salerno (Italy), 2003, p.855-858.
S. Wijskamp, R. Akkerman & E.A.D Lamers, Residual stresses in non-symmetrical carbon/epoxy laminates, ICCM-14, San Diego (USA), 2003
E.A.D. Lamers, S. Wijskamp & R. Akkerman, Drape Modelling of Multi-Layered Composites, 6th ESAFORM conference Salerno (Italy), 2003, p.823-826.
E.A.D. Lamers, S.Wijskamp, R. Akkerman, Modelling shape distortions in composite products, 7th ESAFORM Conference, Trondheim, 2004.
S. Wijskamp, E.A.D. Lamers and R. Akkerman, Spring-forward in composite plate elements, in: Proceedings of the 8th Esaform Conference on Material Forming, Cluj-Napoca (Romania), 2005, p.943-946.
S. Wijskamp, Shape Distortions in Composites Forming, PhD thesis University of Twente, 2005, ISBN 90‑365‑2175‑0.
Sebastiaan Wijskamp is currently employed by Ten Cate AC in the Netherlands (www.tencate.com).