Effect of Thermal-Cold Cycling on Properties of Glass Fiber/ Epoxy Resin Composite for Wind Turbin Blade

The weight loss rate, FTIR characteristic, static mechanical properties and dynamic mechanical properties of neat epoxy resin and glass fiber/ epoxy resin laminates (GF/EP) after thermal-cold cycling were studied in this paper. The rule of static tensile and flexural strength of neat epoxy resin and GF/EP after ageing was investigated through the static mechanical properties analysis. The ageing mechanism of GF/EP was studied by analyzing the storage modulus (E′), loss modulus (E"), loss factor of GF/EP and FITR of epoxy resin. The results show that the weight loss rate increases with the ageing time，which is up to 9% after 400 times ageing cycle. The strength and flexural strength of GF/EP decreased by 6% and 21% after ageing, while the tensile strength of neat epoxy resin increases by 8% and its flexural strength increases slightly after ageing. The mechanism analysis reveals that internal defects of GF/EP would be induced by thermal-cold cycling stress, which results in the interface bonding strength dropping and the performance reducing.