Experimental investigation of textile permeability in the presence of spherical inclusions

Abstract

Addition of a third material phase to a resin and reinforcement system is a favored approach to tailor properties and features of composite materials, including but not limited to the ease of stacking and preforming, or healing ability. This addition changes the structure of the empty spaces between the reinforcing fibers and thus the overall permeability is affected. In this study, the effect of model rigid spherical inclusions on the permeability of woven textiles is investigated. Several diameter ranges of glass beads (40.0-70.0, 70.0-100, 100-200, 200-300, 300-400, and 400-800 μm) with a volume fraction of 5.0% are manually sieved between the layers of a plain weave glass textile, which has a bundle-interstice gap in 150-200 μm range. Experiments are repeated for 2.5 and 10% volume fractions for three diameter ranges (40.0-70.0, 100-200, and 400-800 μm) to investigate the influence of the concentration of inclusions on permeability. Experimental results show that an increase in the diameter or an increase in the volume fraction of the rigid inclusions causes a non-monotonic change in permeability. For all diameter ranges, the ratio between saturated and unsaturated permeability decreases as the volume fraction of beads increases, indicating that capillarity effects may decrease due to blocked flow channels between the fabric layers. © 2016, European Conference on Composite Materials, ECCM.