Study of rate dependent behavior of glass/epoxy composites with nanofillers using non-contact strain measurement

The present research work discusses the effect of strain rate and clay on the dynamic tensile behavior of glass/epoxy composites. Nanocomposites of different clay content in terms of 1.5, 3 and 5 wt% are chosen for the study. Characterization of the nanoclay dispersed in epoxy system is investigated by X-ray Diffraction (XRD) and Fourier Transform Infra-red Spectroscopy (FT-IR), respectively. The non-contact Digital Image Correlation (DIC) technique is used for full-field strain measurement during dynamic loading using high speed CMOS camera. Stress-strain measurements are reported for glass/epoxy/clay nanocomposites over a wide range of strain rates from 0.001 to 450 s−1 and the variation of modulus, strength and strain to failure with strain rate are studied. A non-linear regression function is used to predict the tensile properties of glass/epoxy and its clay nanocomposites. The results show that the tensile strength and stiffness increase with increase in strain rate for neat glass/epoxy and its clay nanocomposites. An improvement in tensile modulus and strength is achieved with the addition of nanoclay. The fractography of tensile specimens is investigated using scanning electron microscopy (SEM) to discern the surface features and dispersion state of clay.