Effect of fabric structure and polymer matrix on flexural strength, interlaminar shear stress, and energy dissipation of glass fiber-reinforced polymer composites

We report the effect of glass fiber structure and the epoxy polymer system on the flexural strength, interlaminar shear stress (ILSS), and energy absorption properties of glass fiber-reinforced polymer (GFRP) composites. Four different GFRP composites were fabricated from two glass fiber textiles of different fabric count and strand density and two resin systems, a cycloaliphatic and a linear aliphatic system. These composites were fabricated using the vacuum-assisted resin transfer method. The flexural stress and ILSS data were obtained using a three-point bending test following ASTM 790-10 and ASTM D2344/D2344M standards. The GFRP composite sheet fabricated using a larger fabric count showed weak flexural strength as well as poor ILSS properties. However, it showed an average increase in energy dissipation of 95% and 7%, for resins SC780 and SC15, respectively, after five compression cycles over the measured range of compression strain. In comparison with the SC15 resin, the SC780 resin proved to have better flexural and ILSS properties but decreased energy dissipation. The results of this investigation help with the design of textile-reinforced composites for applications where bending strength, ILSS, and energy absorption are important.