A stochastic approach to model void formation during out-of-autoclave prepreg consolidation

Material variability is always present in prepreg materials. Accompanied by fluctuations in process parameters, handling and environmental conditions, these inherent uncertainties can lead to significant variations in void content within the final part. This is especially critical for processing thermoset Out-of-Autoclave (OoA) prepregs since the safeguard provided by high autoclave pressure no longer exists. For a more realistic simulation of void formation during OoA processing, contingencies in input parameters have to be considered. Stochastic models are suitable to account for random input factors in order to quantify process output variations. This is a prerequisite to reduce the risk of unserviceable quality of parts to a minimum. The following study attempts to allocate different input variabilities to three types of voids in OoA prepregs and highlights stochastic approaches to model each of them individually.