A SIMULATION OF REINFORCEMENT DEFORMATION DURING THE PRODUCTION OF PREFORMS FOR LIQUID MOLDING PROCESSES

Composite materials offer an attractive alternative to metals in the automative abd aerospace industries. Of the many possible production methods, liquid moulding processes such as resin transfer moulding (RTM) and structural reaction injection moulding (SRIM) demonstrate potential for high-volume manufacture. It is common to use preformed reinforcements, although this can cause certain problems. Fibre movement during forming can cause adverse effects such as wrinkling and thinning. The high levels of waste generated by subsequent trimming operations are proving unacceptable for medium to high volumes. An accurate modelling capability would allow defects to be predicted at the design stage, and would also allow prediction of the net-shape reinforcement required to form the component with no waste. This paper presents models for both random and directional reinforcement deformation. Random reinforcements are simulated using a modified plasticity theory, while directional reinforcements are modelled using the pin-jointed deformation model.