Cavitation Erosion Performance of Fiber Reinforced Composites

Abstract

The cavitation damage resistance of several fiber reinforced polymeric composite systems was evaluated before and after seawater immersion via a modified ASTM G-32 method utilizing a stationary specimen. For both dry and saturated condi tions, a carbon fiber/thermoplastic toughened epoxy matrix composite (IM7/977-2T) was found to perform the best under cavitation attack, while carbon fiber/thermoplastic matrix (AS4/PEEK) was found to be the least resistant. Glass/epoxy composites (E-Glass/5920, Scotch Ply 1002) were intermediate in erosion resistance. Moisture absorption was seen to decrease the erosion resistance of both E-Glass/5920 and AS4/APC-2 materials, while increasing the resistance of SP 1002; IM7/977-2T was not affected by immersion. All mate rials show decreasing erosion rates due to material recession from the cavitation cloud and increasing collapse-shielding with exposure time. A reduction in water hammer pressure was estimated by incorporating finite material impedance into the water hammer equation. Using simplifying assumptions, a 15 percent reduction in water hammer pressure is calculated.