Analysis Of Resistance To Impact Properties And Performance Evolution Of Glass Fiber Composites After UV,high Temperature Aging

With the growing shortage of petrochemical energy resources and the increasingly serious environmental pollution problems,renewable clean energy has become a research hotspot in countries around the world.As a renewable energy source with huge content,no pollution,and rapid development,wind energy is increasingly being received by various countries in the world.The importance is attached;the main component for capturing wind energy is the fan blade,and the performance requirements of the blade on various aspects of the material are relatively strict.It is necessary for us to conduct a comprehensive study on the blade material.The working environment of materials is often very bad,and it is inevitably affected by environmental factors(such as temperature,ultraviolet light,air,humidity,etc.).At the same time,the disadvantage of being more sensitive to impact damage also limits the performance of the material.Therefore,considering the effects of ultraviolet radiation,high-temperature aging and impact on composite materials,this material has guiding significance in engineering application.In this paper,the glass fiber reinforced epoxy vinyl ester resin composite(GF/EVE)were treated under different environment,which include UV radiation,thermal aging and low energy impact.The performance evolution of composite were studied,and the mechanical properties of it after the superposition of UV radiation,thermal aging and impact are in the consideration.The result show that the surface color of the sample gradually yellowing,cracking,warping can be observed after UV radiation,mass loss and a decline of hardness are also accompanied.XPS analysis shows that the contents of C and O elements on the surface will change after UV radiation for a long time;FTIR analysis shows that there is no new and old functional groups,but the intensity of the functional groups change.Thermogravimetric analysis shows that the initial decomposition temperature of the sample is reduced to some extent,but the glass transition temperature of the material is in creased.The tensile strength and bending strength of the samples decrease by 7.8% and 9.88% for 40 d radiation respectively.the surface of the sample cracking,warping can be observed after aging at 120?,and the fibers were exposed on the surface of the specimen due to shr inkage of the resin.XPS,FTIR analysis show that the contents of elements and functional groups on the surface have been changed.The tensile strength and bending strength of the samples decrease by 7.04% and 10.77% for 28 d aging respectively.When low energy impact of 2.5J,5J,7.5J,10 J and 12.5J acts on the samples,the surface of the sample showed pits,matrix cracks,matrix shedding,and fiber breakage.When the impact energy increases to a certain value,the delamination will be appear.When the samples are impacted by 12.5J is thermal-aging for 28 d,the tensile strength and bending strength decrease by 46.98% and 62.79% respectively.the samples are impacted by 12.5J is radiation by UV for 40 d,the tensile strength and bending strength decrease by 46.25% and 61.3% respectively.When the specimens were subjected to high temperature aging,they were impacted by different energy.When the impact energy was 12.5 J,the specimens showed obvious indentations on the front surface,and the damage degree of the specimens gradually became less pronounced with the aging time;When the impact energy is 25 J,the indentation and delamination of the sample are more obvious,and the damage area is larger.As the aging time increases,the maximum impact load on the specimen gradually decreases.Under the same aging conditions,the maximum impact load of the specimen increases with the increase of impact energy;The absorbed energy of the sample gradually increases with the aging time.