Understanding tack behaviour during prepreg-based composites’ processing

Prepreg tack is a critical material property that plays a key role in Automated Fibre Placement (AFP) manufacture-induced defect generation. However, there is a gap in current state-of-the-art manufacturing process modelling that includes tack phenomena and experimental data that shows the influence of multiple factors. In this paper, a modified probe test method, which is capable of inter-ply and ply-tool tack measurement, is proposed. The influence of multiple factors, consistent with the AFP deposition process (i.e. pull-off rate, contact time, pressure and temperature) on tack is studied. Further, a comprehensive modelling framework accounting for all the factors is developed and implemented as a user subroutine for a commercial finite element (FE) package. The work highlights the complexity of tack behaviour at play and shows promise for filling the gap between the tack data/model scarcity and simulation of manufacturing processes such as AFP and forming.