Performance of Composite Materials Subjected to Salt Water Environments

This paper presents the recent trends in the mechanical characterization of composite systems under consideration for Marine Hydro Kinetic (MHK) applications exposed to salt water environments. First, a testing protocol for environmental effects has been developed for resin infused in-house fabricated laminates. Unidirectional ([0] and [90]) mechanical test samples were submerged in synthetic sea water at 40°C and 50°C, with the weight recorded at time intervals over the entire period. Additional witness coupons were submerged to monitor effects of fiber orientation and cure temperature. Next, after conditioning to both full saturation and partial saturation, static compressive and tensile strength properties at temperatures of 0°C, 20°C and 40°C were collected. These results show trends of reduced tensile and compressive strength with increasing moisture and temperature in the 0° (longitudinal) direction. In the 90° (transverse) direction, compression strength decreases but tensile strength is little affected as temperature and moisture increase. Finally, both mechanical and chemical analysis results are presented for samples conditioned in a Salt Fog Chamber for unidirectional, [0] and [90], samples.