Interfacial and mechanical properties with different permeability for three patterned glass Fiber/Epoxy composites by VARTM

Abstract

The interfacial properties for three different glass fiber (GF) mats in epoxy matrix were evaluated by permeability by combining the wettability and interlaminar shear strength (ILSS). The GF mats studied were unidirectional (UD), bidirectional (BD, 0/90 degree), and randomly-chopped (RC) mats. Statistical distributions using single fiber tensile test were compared for 3 GF mats, where forty single fibers were extracted from the fibers in each mat. The extent of damage of the GF in the mats was observed by FE-SEM. The UD type GF mat exhibited the best mechanical properties whereas less damage was observed. Glass fiber reinforced composite (GFRC) specimen, with the three different mat types, was manufactured by vacuum assisted resin transfer molding (VARTM). During manufacture of the GFRC, the permeability of the different GF mats was measured and related to the spreading of epoxy resin in the GF mats. Short beam tests were performed as a measure of interfacial properties and related to the observed permeability and spreading. GFRC manufactured with UD GF mat exhibited the best interfacial and mechanical properties and displayed the least physical damage while GFRC manufactured with BD GF mat had the poorest interfacial and mechanical properties while experiencing the most damage. The UD GF mat also displayed the smallest contact angle change and the best permeability. The longitudinal fiber pattern of the UD GF mat apparently promotes capillary effects leading to an increase in the wetting rate. This study demonstrates that GF mat patterns affect interfacial and mechanical properties as well as mat permeability and resin spreading ability. © 2017 The Composites and Advanced Materials Expo (CAMX). All rights reserved.