CAVITATION EROSION PERFORMANCE OF FIBER-REINFORCED COMPOSITES

The cavitation damage resistance of several fiber reinforced polymeric composite systems was evaluated before and after seawater immersion v ia a modified ASTM G-32 method utilizing a stationary specimen. For bo th dry and saturated conditions, a carbon fiber/thermoplastic toughene d epoxy matrix composite (IM7/977-2T) was found to perform the best un der cavitation attack, while carbon fiber/thermoplastic matrix (AS4/PE EK) was found to be the least resistant. Glass/epoxy composites (E-Gla ss/5920, Scotch Ply 1002) were intermediate in erosion resistance. Moi sture absorption was seen to decrease the erosion resistance of both E -Glass/5920 and AS4/APC-2 materials, while increasing the resistance o f SP 1002; IM7/977-2T was not affected by immersion. All materials sho w decreasing erosion rates due to material recession from the cavitati on cloud and increasing collapse-shielding with exposure time. A reduc tion in water hammer pressure was estimated by incorporating finite ma terial impedance into the water hammer equation. Using simplifying ass umptions, a 15 percent reduction in water hammer pressure is calculate d.