Date of Award
Master of Science
Civil, Construction, and Environmental Engineering
With today's global capacity exceeding 280 GW, windpower has proven to be a formidable source of renewable energy worldwide. In order to keep pace with the growing demand, the wind industry will need to overcome challenges associated with low alternative energy costs without depending upon any form of government subsidy. A major research effort has been focused on reducing the capital, production, and maintenance costs through the use of taller wind turbine towers. Today's turbines often consist of 262 ft (80 m) steel towers. As taller towers become more desirable, material and transportation costs associated with steel tower designs grow significantly. The increase from 262 ft (80 m) to 328 ft (100 m), allows turbines to access the improved wind conditions that exist at higher elevations.
A new tower concept has been developed using Ultra-High Performance Concrete (UHPC) and other high strength concrete materials that would allow taller wind turbine towers to be transported to wind farm sites easily within the current transportation limitations. Three tower designs, consisting of precast UHPC and high strength concrete segments, have been completed for potential field implementation. By utilizing different combinations of these materials, each design offers unique benefits related to costs, tower weight, connection design, etc.
In order to verify the design of each of the three towers, experimental testing was completed using full-scale precast components. Each was found to be the most critical tower component at the governing load case thorough the use of a finite element modeling. The tests provided insight into the performance of the various panel, and precast connection designs specifically developed for each wind turbine tower. By assessing the performance at both the operational and extreme limit states, it was concluded that each specimen responded exceptionally well. In addition to verifying the capacity of each tower, observations made during construction offered insight into future construction practices. Using the results of these tests, appropriate modifications were made to the design making it suitable for full-scale implementation in the wind industry.
Grant M. Schmitz
Schmitz, Grant M., "Design and experimental validation of 328 ft (100 m) tall wind turbine towers utilizing high strength and ultra-high performance concrete" (2013). Graduate Theses and Dissertations. 13364.