MODELLING THE TEMPERATURE DEPENDENT VISCOELASTIC COMPACTION BEHAVIOUR OF UNCURED PREPREGS

In autoclave processes like ATL and AFP, and out-of-autoclave manufacturing processes like SQRTM, prepreg layers are compacted at temperatures higher than room temperature, for better flow of resin into the layers. For process modelling of such manufacturing techniques, there is a need to develop a model that can predict the thermoviscoelastic compaction response of prepregs at different temperatures. For experimental study, single step relaxation experiments for different rates and temperatures are carried out on a glass fiber/ epoxy resin matrix prepreg. A thermo-hyper-viscoelastic numerical model was developed within thermodynamics framework incorporating the traditional compaction model and temperature scaling function to capture rate dependent thermo-viscoelastic response during compaction and relaxation phenomena in uncured prepreg.