In-situ elevated temperature flexural and creep response of inter-ply glass/carbon hybrid FRP composites

Abstract

Inter-ply fiber hybridization is a promising technique for tailoring the mechanical properties of FRP composites. But the durability of these composites under combined exposure to thermal and flexural loading is still unexplored. In this study, the effect of temperature on the flexural and creep performance of glass/epoxy (GE), carbon/epoxy (CE) and glass/carbon/epoxy (GCE) hybrid composites has been studied. Replacing 2 GE plies at each side (top and bottom) by equal number of CE plies in a 7 layered composite resulted 83% and 112% improvement in strength and modulus respectively at room temperature. With increase in temperature, both strength and stiffness of all the composites continued to decrease upto the highest testing temperature (110 °C). Interestingly, it was noticed that composites containing more number of CE plies degrade at a faster rate, but still a positive hybrid effect in terms of strength and stiffness was noticed upto a temperature of 90 °C. The dominating failure mechanisms were analysed from their micrographs for different composites at different testing temperatures. The dynamic mechanical thermal analysis of all the materials was studied in the temperature range of 40 – 200 °C. The creep study at elevated temperature indicates the synergetic effect of both glass and carbon fibers in the hybrid composite.