Static and dynamic fatigue of glass-carbon hybrid composites in fluid environment

Unidirectional glass fiber reinforced and glass-carbon fiber reinforced epoxy matrix composite samples (% glass to carbon fiber volume ratio 90: 10 and 75:25) were subject to two-point bend rupture test in distilled water at 75°C and tension-tension cyclic test in both air and distilled water at 25°C. In the rupture test, while no obvious difference in rupture time was observed at larger deflections, glass-carbon hybrid samples showed prolonged rupture time in comparison to all-glass samples when loaded at 10% maximum deflection. When compared to samples tests in air, cyclic loading in water resulted in shorter fatigue lives for both all-glass and hybrid composite samples. However, hybrid samples showed better environmental fatigue resistance in water than all-glass samples, to 10⁷ cycles. By incorporating appropriate amount of carbon fibers in glass fiber composite, long-term performance of glass-carbon hybrid composites under static and dynamic fatigue is substantially enhanced. It is demonstrated by the present study that the intra-ply hybrid approach is effective and economical in improving the durability of fiber reinforced polymer composites for long term applications.