Durability Experimental Investigation Of Glass Fiber Reinforced Polymer Sheet In Hygrothermal Environment

With the widely used in many fields,the durability of fiber reinforced polymer/plastic(FRP)has been becoming a research hotspot.Failure test method is used in experimental investigation to study the durability of FRP.Due to the highly design ability and the difference in initial mechanical properties of FRP,it's different that the specimens comes from different researchers and batches.So that the base point of the test results was different,and there is no universal standard for the durability research achievements of FRP.As a consequence,the guiding significance of the durability research achievements to the engineering application was limited.To solve this key matter in the durability research of FRP,the non-failure test method was raised for the first time.The core idea of the method is,throughout the whole aging period,each specimen is tested for many times without damage at a specific control level.In this way,the changing rules of the elastic modulus with time can be found,which have same base point.In order to realize the non-failure test of FRP,the buffer unit was invented,the tension method comparative study was completed,which was including 15 GFRP sheet specimens for 247 times tension test.The influence of the non-failure test method and the failure test method to test results was compared.The control means(including force control and deformation control)and control levels(including 15%,20%,30%,40% and 50%)of the non-failure test method were researched.According to the results,when using the non-failure test method to test the elastic modulus of FRP,the force co ntrol method and 20% to 30% control levels should be used.In this way,the operability of the method in test and the effectiveness of the buffer unit are confirmed.The durability investigation of GFRP sheet in hygrothermal environment for 6 months was carried out.Based on the non-failure test method and failure test method,the elastic modulus of 56 GFRP sheet specimens came from 8 batches and 14 resin specimens were tested,the change rules of elastic modulus with aging time of GFRP sheets were analyzed.The similarity of the non-failure and failure test method was proved.