Development of High Strength, High Fatigue Wind Blade Spars

The size of the latest generation of wind turbines is outstripping the capabilities of the materials and techniques used to manufacture them. As wind turbines are made larger to improve efficiency, composites with improved mechanical properties and long term performance are required to avoid premature field failures. Further as wind turbines are produced in ever greater numbers, faster manufacturing techniques with improved consistency and quality assurance are required. This SBIR Phase II will develop and demonstrate the feasibility of a novel composite and manufacturing method which combines higher strength, improved fatigue resistance and the possibility to significantly increase manufacturing throughput. The proposed new composite will enable larger, more efficient wind blades to be produced, aiding the safe rapid expansion of one of the most cost effective forms of alternative energy. In Phase I the feasibility of using vacuum infusion to bond together multiple high strength pultruded rods to produce a larger composite profile was demonstrated. The properties of multiple profiles were tested and shown to have improved strength and stiffness properties and exceptional compression fatigue properties compared with existing wind blade spar materials. In Phase II additional materials data, manufacturing scale up methods and design details will be developed leading to the design of a complete wind blade utilizing the newly developed composite system. The work will result in a full performance comparison demonstrating the advantages of the proposed technology over existing materials and production methods. Commercial Applications and Other Benefits: Implementation of the proposed technology will result in future wind blades with improved efficiency, improved longevity and reduced manufacturing cost.