Analytic method to estimate multiple equivalent permeability components from a single rectilinear experiment in liquid composite molding processes

Presented is an approach for determining multiple permeability components from a single rectilinear experiment modeled similarly to a VARTM infusion. Values are estimated for in-plane and transverse (through-thickness) permeability of the fabric, as well as distribution media permeability in the flow direction. An effective permeability for the combination of fabric and distribution media is also defined. The approach is based on tracking the resin flow-front during linear infusion along the top and the bottom surface over a sample representing several material layups (a segment of which includes the flow enhancement media). Analytic solution of flow progression is used to derive estimates for permeability of all components/layups. The solution, the error due to the assumptions and approximations made, and its limits of applicability are presented. Experimental validation is also provided. Numerical techniques using flow simulation results are utilized to execute a data correction algorithm to further improve experimental estimates.