Analysis of mesoscopic pore size in 3D-interlock fabrics and validation of a predictive permeability model

Abstract

This paper reports an experimental investigation aiming to validate a predictive model of in-plane and transverse permeability for three-dimensional interlock fabrics as a function of fabric architecture. Composite specimens were fabricated and cut to conduct microscopic observations of pore dimensions for five three-dimensional interlock fabrics compressed to a fiber volume content of 58%. The pore cross-section height and width, the number of pores and the pore tortuosity were measured to evaluate an average pore size and distribution along the warp and weft directions for each fabric considered. The changes of these geometrical parameters are analyzed as a function of the fabric structure. A previously developed permeability analytical model is applied using the geometrical characteristics derived from the experimental observations. This allows comparing the experimental permeability to the theoretical predictions of the model and to the values calculated by the same model from the experimentally observed pore dimensions at the considered fiber volume content of 58%. The good agreement obtained in all cases between the measured and calculated values of permeability confirms the validity of the proposed analytical model.