Braiding simulation for RTM performs
Start / End:
June 2002 to
The project was part of the collaborative research project between the Dutch Aerospace Laboratories (Nederlands Lucht en Ruimtevaartlaboratorium, NLR) and the University of Twente. This project, referred to as the UT-NLR-RTM project, started in May 2001.
Automated braiding is a suitable process to manufacture reproducible preforms for Resin Transfer Moulding (RTM). The highly interlaced structure of braids makes it possible to cover components with sharp curvatures and non-circular cross-sections, varying along the length of the component. Two or three groups of yarns can be mounted on the horn-gear braiding machine. The warp and weft yarns rotate in opposite directions in the spool plane, forming a closed biaxial fabric. Stem yarns can be inserted through the horn gears, leading to a triaxial reinforcement in the axial direction of the mandrel. A pair of guide rings leads the yarns towards the mandrel.
Overbraiding: experiment at Eurocarbon and process simulation
A fast simulation model for braiding on arbitrary geometries was implemented in a user friendly software package. A standard triangular element mesh can be used as the geometry input. A complex preform was used for validation purposes, as shown in the picture above. The overbraiding experiments were performed at Eurocarbon (NL), using glass and black polyester yarns. Digital image analysis was used for subsequent fibre orientation measurements.
The correlation between simulation and experiment is good as long as fibre slip is absent after deposition. As shown in the next figure, tests 2 and 3 were performed with an adhesive layer on the mandrel, Test 1 without. The no-slip results are accurate within the experimental scatter.
Braid angles: measurements vs. simulation results
J.F.A. Kessels & R. Akkerman, Prediction of the yarn trajectories on complex braided preforms, Composites A, 33(8), 2002, pp. 1073-1081.
N. Tan, msc project: Slip prediction in circular braiding
B.H. Villa Rodriguez, Braiding Simulation, Proceedings of ISCM-2, Braunschweig, CD-edition, 2004.
R. Akkerman, B.H. Villa Rodriguez, Braiding simulation for RTM preforms, Proceedings of TEXCOMP-8, Nottingham, UK, 2006.