This research focuses on investigating how the inclusion of interleaving veils with different areal densities influences the mechanical behavior of glass epoxy composites. Commercially available non-woven carbon veils (15, 20 and 30 g/m2) and Glass veils (25 and 30 g/m2) were used as interleaving material. The plain and interleaved composite laminates were manufactured by a hand layup process. The effect of non-woven veil interleaving was estimated through tensile, flexural, short beam shear (SBS), and single-edge notched beam (SENB) mechanical tests. The mechanical test results showed a significant variation in strength with respect to the change in the areal density of interleaving. The veil’s areal density has a significant effect on in-plane and out-of-plane composite strength. An improvement of about 6% in longitudinal tensile strength was observed for the GEC-15 C specimen. In the lateral tensile test, an improved tensile strength was observed for the veil interleaved samples. Besides, the marginal improvement was also observed for the GEC-15 C specimen under open hole tensile strength. Further, considerable enhancement of about 13%, 24%, and 44% was noticed in flexural, interlaminar shear strength (ILSS) and fracture toughness for 20 g/m2 carbon veil interleaved samples, respectively. The experimental results are presented by providing mean, standard deviation, and coefficient of variation (COV) with 4% to 10% across all the loading modes. Further, scanning electron microscopy (SEM) characterization of SENB specimen revealed that fiber pullout, matrix deformation, and fiber-matrix deboning etc., served as critical elements in improving the fracture toughness of composites reinforced with interleaving veils.
Gouda et al. (2026) studied this question.