The effect of nesting on the in‐plane permeability of unidirectional fabrics in resin transfer molding

The nesting of layers has great effect on the permeability, which is a key parameter in resin transfer molding. In this article, two mathematical models were developed to predict the in‐plane permeability of unidirectional fabrics with minimum and maximum nesting, respectively. For different zones of characteristic yarn arrangement in the unit cell, the local permeability was modeled as a function of geometrical yarn parameters. The global permeability was then modeled as a mixture of permeabilities of different zones with the electrical resistance analogy. A reasonably good agreement was found between the model predictions and experimental results. We also found that at the same fiber volume fraction, the results for Ky were two times larger with minimum nesting than with maximum nesting, whereas the results for Kx were a little lower with minimum nesting than maximum nesting. In addition, the differences between minimum and maximum nesting decreased with increasing fiber volume fraction. POLYM. COMPOS., 37:1695–1704, 2016. © 2014 Society of Plastics Engineers