Evaluating Performance of Composite Materials for MHK Applications

Abstract

Montana State University (MSU) has a compilation of material systems, environmental chambers, and mechanical testing equipment to determine composite materials performance and failure characteristics. Mechanical characterization of composite systems will provide direct quantification of the materials under consideration for Marine Hydro Kinetic (MHK) designs that were initially developed for the wind turbine industry. The work presented herein represents the testing protocol development and initial results to support investigations on the effect of sea water absorption on material strength. A testing protocol for environmental effects has been developed for the resin infused in-house fabricated laminates. Unidirectional ([0] and [90]) test samples of 2-mm and 6-mm thickness were be submerged for 1000 hours in synthetic sea water at 40°C with the weight recorded at time intervals over the entire period. After 1000 hours of conditioning, coupons were placed in the synthetic sea water at 20°C until testing. Static compressive and tensile strength properties at temperatures of 5°C, 20°C and 40°C were collected. These initial 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. Elastic modulus (E) is little affected in the longitudinal direction but decreases in the transverse direction.