Effect of in-situ temperature and loading rate on the out-of-plane performance of carbon nanofiber embedded glass fiber / epoxy composite

This article studies the influence of in-situ temperatures (30 °C, 60 °C, 90 °C, and 120 °C) and loading rates (1 mm/min and 100 mm/min) on the out-of-plane flexural performance of Glass fiber reinforced epoxy composite with and without carbon nanofiber (CNF) (GE and CNF-GE). Improved stress transfer in CNF-GE composites than GE composite resulted in enhanced flexural properties at 30 °C. The crack propagation time is reduced as the loading rate increases. Due to the substantial obstruction of CNF against crack propagation, CNF-GE composites displayed higher flexural properties than GE composites. However, with the rise in temperature over 60 °C, CNF-GE composites showed a severe decrement in flexural properties than GE composites due to the generation of thermal stresses at the CNF/epoxy interface. The evidence of interfacial debonding at the fiber/epoxy and CNF/epoxy was obtained through fractography, satisfying the explanation provided during flexural analysis.