EXPERIMENTAL STUDY ON TENSILE PROPERTIES OF CFRP GRIDS UNDER THE COUPLING OF SEAWATER IMMERSION AND STRESS

In order to study the change law of the tensile mechanical properties of CFRP (Carbon Fiber Reinforced Polymer) grids in marine corrosive environment, a single-limb tensile performance test of CFRP grids with different initial stress levels in seawater environment was carried out. The results show that the degree of surface erosion of the CFRP grid increases with aging time, the surface color becomes darker, the original gloss of the matrix is lost, and it becomes rough; the failure mode is from the tensile failure of most specimens in the early stage to the burst failure in the later stage. At the level of (0.6 f_u), individual specimens showed layered damage, and the damage was more obvious. In addition, after immersed in seawater for 360 days, the retention rates of tensile strength of CFRP grids with stress levels of 0, 0.3 f_u and 0.6 f_u were 89.8%, 87.7% and 79.8%, respectively, and the retention rates of elastic modulus were 96.4% and 95.0% and 92.9%, respectively. Indicating that the presence of stress accelerates the degradation of the mesh strength, and as the stress level increases, the degradation of the tensile strength and elastic modulus of the CFRP mesh becomes more obvious.