ABSTRACT
Long-term durability in demanding operating conditions is one of the key features that defines the value of composite materials. To improve the understanding of long-term performance and provide a basis for structural design, creep rupture tests were conducted on 6.4-mm (0.25-inch) diameter pultruded rods. By conducting tensile tests under constant load with and without exposure to several environments, the effect of environment on performance was evaluated. Tests were conducted at 23 and 60 degrees Celsius to evaluate the acceleration of the failure process by temperature. Environmental creep rupture performance was evaluated for two sets of pultruded rod samples: one set made with traditional E-glass reinforcements and the second set using a boron-free, low pollution E-glass fiber reinforcement. From the observed behavior plotted as a log-time to log-stress relationship, a reasonable test protocol is available for predicting long-term behavior from short-term testing. Results indicate that environment and temperature do significantly impact creep rupture performance, and composite materials reinforced with the boron-free glass formulation demonstrate superior long-term performance to composite materials made with traditional E-glass reinforcements.
