Prediction of the yarn trajectories on complex braided preforms

Braiding can be used to manufacture preforms for resin transfer moulding (RTM). With braiding, many yarns are used, non-geodesic yarn paths are possible, and the interlaced structure of braids provides typical mechanical properties such as high impact strength. Previously, several models were developed to predict the fibre angles on simple, stationary braided preforms, but not for complex, non-axisymmetric preforms. This paper presents a fast and efficient model to predict the fibre angles on complex biaxially braided preforms. The model is verified with experiments on two mandrels and the experimental and numerical results show good agreement.