Residual compressive strength of filament wound hybrid glass/carbon fibre reinforced polymer tubes after exposure to elevated temperature

Fibre hybridisation is used to balance the high cost of carbon fibres and the low durability performance of glass fibres. This study investigates the residual compressive mechanical properties of filament-wound hybrid glass/carbon Fibre Reinforced Polymer (FRP) tubes after exposure to elevated temperatures. Effects of temperature exposure and fibre orientation on compressive properties have been investigated. Tubes were exposed to temperatures ranging from ambient to 350 °C. Two fibre orientation configurations, including hoop (89°) and cross-ply (20% at 15°, 40% at 40°, and 40% at 75°) were used to study the effect of fibre orientation. Compression tests were carried out to study the compressive mechanical properties of FRP tubes, while Digital Scanning Calorimetry and Thermal Gravimetry Analysis were conducted to study the thermomechanical characteristics of the specimens before and after exposure to the elevated temperatures. Finally, the level of damage and its mechanisms were investigated using Scanning Electron Microscopy. The experimental test results indicate that hybrid carbon/glass FRP (C/GFRP) tubes exhibit a performance closer to the weaker tube type, i.e. CFRP tubes rather than GFRP tubes. Moreover, when subjected to elevated temperature, tubes with cross-ply fibre orientations showed slightly better compressive performance compared to the tubes with a hoop fibre orientation.