Mechanical Performance of Hybrid Composites Under Cryogenic Temperature and Humid Environment

The present investigation intends to study the mechanical behaviour of carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) composites at room temperature and cryogenic temperature. Then carbon and glass fiber hybridisation has been done to see the effect of hybridisation on mechanical properties of composite at both room and cryogenic temperature. Polymer matrix composites (PMC) has been fabricated by hand lay out method consisting of 7 layers. The composites were subjected to three point bend test at room temperature and cryogenic temperature to determine its flexural strength and modulus. In case of GFRP the flexural strength at cryogenic temperature was found out to be 42% more than flexural strength at room temperature whereas the flexural strength was 25% less at cryogenic temperature in case of CFRP. C2G5 hybridisation showed 50% increment in flexural strength at cryogenic temperature. But G5C2 and C2G3C2 type of hybridisation showed 9% and 20% decrement in the flexural strength when tested at cryogenic temperature. Dynamic Mechanical Analysis (DMA) test was done at a temperature range of -150℃ to 200℃ to validate above results and study the viscoelastic nature of these composites. The fracture surface of the composites were studied under Scanning Electron Microscope (SEM) to learn about the fracture mechanism. GFRP, CFRP and glass/carbon hybrid composites were also exposed at 15℃, 90% relative humidity (RH) environment to study the moisture absorption kinetics and mechanical performance of PMCs after moisture intake