| Wind energy is a renewable clean energy and inexhaustible. Thewind turbine blades that play a key role to collect wind energy aregenerally regarded as one of the most critical component of the windturbine system. Wind turbine blade is exposed to various hostileconditions during its service process. In order to ensure the safety of windturbine blade during the whole service lifetime20years, it is necessary tostudy the weather resistance properties of composite materials for windturbine blade.In this paper, the weather resistance properties of epoxy (EP) resinmatrix and its glass fiber reinforced composites (GFRP) wereinvestigated through artificial accelerating ageing, such as cold-thermalageing, salt spray ageing and hydrothermal ageing. The effects of ageingon apparent properties, mechanical properties, heat resistance andmicro-properties of resin matrix and its composites GFRP wereinvestigated to study the ageing mechanism of composite materials forwind turbine blade.The results of cold-thermal cycling ageing show that the tensile andflexural strength of resin matrix increase at beginning then decrease withageing time. After400times cold-thermal cycling ageing, the mass lossof GFRP is reached9%, the Barcol hardness is decreased by9%forGFRP, the tensile and flexural strength of GFRP is decreased by5%and27%, respectively. The Tgof resin matrix is reached to the maximumdegree75℃after160times cold-thermal cycling ageing. Then the Tgofresin matrix decreases with ageing time, which is declined to71℃after400times cold-thermal cycling ageing. The storage modulus (E′) of resinmatrix decreases with ageing time during cold-thermal cycling ageing,and the storage modulus (E′) of GFRP increases at beginning thendecreases with ageing time.The results of salt spray ageing show that the tensile and flexuralstrength of resin matrix is decreased by15%and17%respectively after100days salt spray ageing, and the tensile and flexural strength of GFRP is decreased by25%and33%, respectively. The Barcol hardness ofGFRP decreases with ageing time during salt spray ageing. The Tgofresin matrix during salt spray ageing decreases with ageing time, which isdeclined by8℃after100days salt spray ageing. The storage modulus(E′) of resin matrix and GFRP decrease with ageing time during salt sprayageing.The results of hydrothermal ageing show that the Tgof resin matrixafter50days hydrothermal ageing is reached72℃, which is4℃higher than that of un-ageing sample. After100days hydrothermal ageing,the Tgis declined to68℃. The moisture sorption characteristic of GFRPafter hydrothermal ageing is followed by Fick’s law. After100dayshydrothermal ageing, the tensile and flexural strength of GFRP isdecreased by17%and23%, respectively. The storage modulus (E′) ofresin matrix decreases with ageing time during hydrothermal ageing, andthe storage modulus (E′) of GFRP increases at beginning then decreaseswith ageing time. |
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