Sıvı kompozit kalıplamada kullanılan fiber takviyelerin geçirgenlik karakterizasyonu

Experimental setups were designed and constructed to characterize permeability of fabric preforms used in liquid composite molding processes for three different flow dimensions (linear, radial and through-thickness). They allow measuring both unsaturated and saturated permeabilities in linear and radial flows, but only steady (saturated) permeability in through-thickness direction. Four common curve fitting methods (global, single-step, reference time step, elementary methods) are used to fit the analytically expected formulas that are driven from Darcy's Law and conservation of mass experimental data. It is investigated how closely these four curve fitting methods fit to the experimental data by comparing their R-squared values. In agreement with the previous literature, in general there is a very significant variation between the results of the repeated experiments due to inherent variations in the material used and labor of fabric cutting, stacking and placement in the mold. This study contributes to the composite research by investigating which setups, conditions and curve-fitting method are more suitable to model the resin flow through fabric preforms used in Liquid Composite Molding (LCM), and also help decreasing the mentioned variation in 1D and 2D permeability measurements.