Tensile properties of GFRP laminates after exposure to elevated temperatures: Effect of fiber configuration, sample thickness, and time of exposure

This study investigates the tensile properties of various GFRP laminates after exposure to elevated temperatures. Fiber configuration, exposure temperature and laminate thickness were considered as the test variables. A total number of 180 specimens were tested in tension to obtain the mechanical properties of GFRP laminates. Alongside the mechanical tests, SEM analyses were conducted on selected samples before testing to investigate the resin, fiber, and their interface damages. Regardless of the sample type, it was generally observed that the reduction rate in the tensile strength increased with an increase in the exposure time and a decrease in the laminates' thickness. The results of tensile tests after exposure to elevated temperatures showed that the laminates with continuous unidirectional fibers performed the best, laminates with chopped strand randomly distributed fibers performed the worst, and the performance of the laminates with woven continuous fibers was somewhere in between. The maximum tensile strength reductions for the unidirectional and woven laminates were about 50% after exposure to 300 degrees C, whereas random chopped strand laminates lost almost all of their load carrying capacity under this exposure condition.