Fatigue resistance of randomly oriented short glass fiber reinforced polyester composite materials immersed in seawater environment

摘要

Randomly oriented short fiber mat reinforced polyester composite laminates immersed in natural seawater for various periods were tested in static and cyclic fatigue loading under three-point bending conditions. Water absorption increased the weight of the specimen while the extraction of soluble compounds induces a weak weight loss. Wohler curves carried out from repetitive fatigue tests were drawn for the different periods of immersion time. These curves, which are characterized by an important and a significant scatter in their lifetime, were modeled by straight lines. These glass-polyester laminates deteriorate in fatigue tests at a constant rate by cycle decade. This rate increases with increasing immersion time in seawater at a constant speed. A comparison between different mathematical models of endurance curves shows that Wohler's equation gives a good representation of the average part of the curve.