The Mechanical Properties of Nanoclay/E-glass-Epoxy Multiscale Grid Composites under 3-point Bending Test

In this research work, the effect of nanoclay addition on the flexural properties of E-glass/epoxy grid-stiffened composites (GSCs) was investigated. Firstly, in order to the formation of a stronger interface between the matrix and nanoclay particles, the nanoparticles were modified by a silan coupling agent (3-glycidoxypropyltrimethoxysilane/3-GPTS). Unidirectional glass fibers as rib reinforcement, plain glass fibers as skin reinforcement and a mixture of epoxy resin and 0, 1, 3 and 5 weight percent surfacemodified nanoclay as matrix part were used to produce GSCs. The surface modification trend of nanoclay particles was confirmed by Fourier transform infrared (FT-IR) and X-ray diffraction (XRD). Obtained results showed that the addition of the surface modified nanoclays caused the improvement of stiffness, maximum load and energy absorption properties of GSCs, and the maximum improvements was related to the specimen with 5 wt. % nanoclay. It was also found out that a considerable portion of energy absorption was occurred after the primary fracture at peak load, manifesting the high damage tolerance of the grid composite structures.