Synergistic Effects of Fatigue and Marine Environments on Carbon Fiber Vinyl Ester Composites

Abstract

Fiberreinforced polymer (FRP) composites used in the construction of compositebased civil and military marine crafts are often exposed to aggressive elements that include ultraviolet radiation, moisture, and cyclic loadings. With time, these elements can individually and more so cooperatively degrade the mechanical properties and structural integrity of FRP composites. To assist in increasing the longterm reliability of composite marine crafts, this work experimentally investigates the cooperative damaging effects of ultraviolet (UV), moisture, and cyclic loading on the structural integrity of carbon fiber reinforced vinylester marine composite. Results demonstrate that UV and moisture can synergistically interact with fatigue damage mechanisms and accelerate fatigue damage accumulation. For the considered composite, damage and S–N curve models with minimal fitting constants are proposed. The new models are derived by adapting wellknown cumulative fatigue damage models to account for the ability of UV and moisture to accelerate fatigue damaging effects.