PREFORM PERMEABILITY PREDICTIONS BY SELF-CONSISTENT METHOD AND FINITE-ELEMENT SIMULATION

The self-consistent method and finite element simulations have been used to estimate the permeability of an aligned fiber bundle. The self-consistent method gives out formulas for both longitudinal and transverse permeabilities as functions of the fiber volume fraction. The finite element simulation presents the solutions of various periodic fiber packings. The results for square and hexagonal fiber packings are found coincident with the literature results. It is shown that the permeability is not only related to the fiber volume fraction or porosity, but is also greatly influenced by the packing structure or micro-level disturbance. A unified empirical model is proposed, which uses as variables ultimate fiber volume fraction in addition to fiber volume fraction. The model predictions agree with numerical simulation results in different cases.