Impact Damage Tolerance Enhancement of Woven Composites at Extreme Environments

Abstract

According to the US Geological Survey, 22% of the world’s undiscovered resources (natural gas, oil and natural gas) are located in the Arctic. As global temperatures rise, larger windows of arctic water routes are becoming viable. The materials used in the ships that will navigate the Arctic must be able to withstand harsh environments that the arctic routes may bring, with temperatures dropping to -60 °C and ice projectiles impacting the hull. Therefore, when designing ship hulls, the materials selected must be able to withstand thermo-mechanical loads. Polymer matrix composites (PMC) have become a potential option to use in ship hulls due to their high strength-to-weight ratio. However, their mechanical behavior in extreme environments is still unknown. This study investigates the impact behavior of PMC reinforced with finely ground Kevlar pulp as an interlaminar reinforcement to increase the impact damage tolerance at extreme environments. The laminates were manufactured via resin transfer molding (RTM) in a compression press. The dimensions of each sample were 150 mm long by 100 mm wide and a thickness of 4 mm. The impact tests were performed in an Instron CEAST 9340 drop weight impact system using a mass of 5 kg and impact energies of 5 J, 7.5 J, and 10 J, for room and arctic temperatures (-60 °C). Reinforced samples (Kevlar) showed a decrease on the degree of damage (ð·ð‘‘ð‘Žð‘šð‘Žð‘”ð‘’) of ≈20%, a decrease on the bending stiffness of ≈17%, an increase on the peak impact force of ≈5% and a decrease on the displacement of ≈12%. Preliminary results showed that laminates reinforced with Kevlar have higher impact damage tolerance than unreinforced samples.