| Fiber-reinforced composites are increasingly being employed in advanced composite based military marine crafts as they can assist in achieving cost savings, weight reductions and increased stealth capabilities. In these crafts, composites are considered for a wide range of applications, such as for superstructures, decks, bulkheads, masts and propellers, among others. However, in marine applications, composites are often exposed to aggressive environments, which include: ultraviolet radiation, salt water and cyclic loadings, to name a few. With time, such harsh elements can individually and cooperatively degrade the mechanical properties of fiber-reinforced polymer composites, diminishing their structural integrity and durability. Accordingly, ensuring the long-term reliability of composite marine crafts is instrumentally tied to characterizing the damaging effects of marine environments on fiber composites, particularly the synergistic effects as they are more severe, harder to anticipate and are not well-understood. Therefore, this work experimentally investigates the cooperative damaging effects of the long-term combined exposure to UV radiation, moisture and cyclic (i.e. fatigue) loading on the structural integrity of the marine composite (carbon fiber reinforced vinyl-ester composite). Results demonstrate that UV radiation and moisture have synergistic deleterious effects on carbon fiber-vinyl ester composites and when combined with cyclic loading can accelerate and amplify the accumulated damage and reduce the composites' life. |
