Study On Aging Of Two Kinds Of Glass Fiber Reinforced Composites In Moist Environment

Glass Fiber Reinforced Plastic?GFRP?becauses of its light weight and high strength,good design,good weather resistance,can produce excellent performance functional material has been widely used in the area of military domain as aerospace,Marine vessels,Missile satellite and civilian area such as transportation,electronic agriculture and energy.The total production of GFRP in China ranked second around the world in 2006 and in 2007,the total production of glass fiber ranked first in the world.In recent years,the GFRP has a rapid growth use in the area of civil architecture and bridge area.However,how to maintain the durability of GFRP is a urgent question to be solve,and study the mechanism of degradation in the moisture circumstance is essential.This paper present a method of obtain two different kinds of GFRP sample that made by two types of glass fiber and resign,through Hand Lay-up Molding and vacuum assisted resin infusion.Thoroughly Researched their microscopic appearance,water absorption,Barcol hardness and bending property under the following five manners:immerse in 3 5? water,65? water,salt spray,salt spray-water immerse atmosphere and water immerse-salt spray atmosphere.On the basis of summarizing the predecessors' achievements,explored the GFRP material ageing mechanism when its under the condition of the moisture circumstances,then obtain a highly match formula to the Life prediction equation,and calculated the relationship between the temperature and ageing.The study shows that GFRP may present a immense change in the appearance and property.First,the exterior change of GFRP mainly appears in color and transparency.The ageing material turns to white and turbidity,some of them even become yellowing.Second,there different circumstances have a great influence to the two kind GFRP material,especially for the Barcol hardness.The composition of the material determine the property,the temperature is the second factor and the salt spray circumstance is the third.The Barcol hardness attenuating in vacuum system is 143%higher than in hand lay-up system,in 65? is 88.7%higher than in 35? and in the salt spray circumstance is 27.3%higher than in 35?.Third,the composition of the material is the most factor influence to water absorption,the temperature is the second factor,and the salt spray is the third.The water absorption attenuating in vacuum system is 56.27%lower than in hand lay-up system,in 65? immersion is 28.9%higher than in 35? and in the salt spray circumstance is 21.85%higher than in 35?immersion.Fourth,five different circumstances and different systems have a great influence on the GFRP material blend strength.Fifth,the coefficient of multiple determination for fitting formula of intermediate value formula is 13.53%higher than kinetic model formula?use all the metrical data?,and 2.3%higher than the situation that wipe out the initial value.Sixth,through the blending theory,we get a equation about a method of life prediction,and figure out two different Life transformation equation:t₁/?t₂ = e^12896?1/T₁-1/T₂??apply to hand lay-up system and t₁/?t₂ = e^22135?1/T₁-1/T₂??apply to the vacuum system.