Abstract
Voids, that could be the origin of fractures in composite materials, are likely formed in between filaments during resin impregnation. To reduce these microvoids, it is important to clarify the mechanism of microvoid generation. In our previous study, we constructed an experimental model using a microfluidic-device in which many pillars have been arranged hexagonally and observed the flow behavior during microvoid generation. Our results showed that microvoid generation correlates to velocity, viscosity of the fluid and geometric distance between adjacent pillars. To evaluate these relationships without cumulative effects arisen from surrounded pillars and random shape of the flow front, we constructed another microfluidic-device in which two pillars are aligned with a distance along the flow direction. Using this simplified experimental model, our results showed that there is velocity criterion in determination of microvoid generation.
