A novel mold design for one-continuous permeability measurement of fiber preforms

Abstract

One-continuous permeability measurement experiments allow measuring permeability of a fiber preform within a range of fiber volume fractions by conducting a single unsaturated (a.k.a. transient) flow experiment on a dry specimen at an initial thickness, and a set of saturated flow experiments on the wetted specimen by varying the thickness of the mold cavity. This approach allows quicker database construction and reduces the effect of inherent variation of fabric structure caused by inconsistent labor on permeability. In this study, the drawbacks of previous mold designs are eliminated by using appropriate sealing, gap thickness adjustment mechanism and features that allow straightforward and reliable manual operation. Experiments for three different fabric types are conducted and the results are discussed. It is mainly observed that the unsaturated permeability is higher than the saturated permeability.