Environmental degradation of flexural and fracture properties of glass/vinyl ester filament wound pipes

An experimental testing program is being conducted to evaluate the effects of environmental exposure on the mechanical properties of glass/vinyl ester filament wound pipes. The effects of artificial exposure on the flexural and fracture properties are reported in this paper. Three point bending specimens were employed to characterize the flexural properties. Fracture resistance was assessed using pre-cracked notched ring specimens. Specimens were exposed for 300, 1000, and 3000 hours in the environment of interest before testing at room temperature. The exposure conditions presented in this paper include: dry heat at 401, dry heat at 701, 65% and 100% relative humidity at room temperature; and salt spray and seawater environments at room temperature. The results of this study indicate that the flexural strength and stiffness; and the fracture resistance of the tested GFRP composite do not show significant degradation due to prior exposure to the environments investigated for up to 3000 hours. The flexural ductility is shown to degrade after exposure in high humidity environment.