Partial Fulfillment of the Requirements for the Degree of Master of Engineering

A support tower is the main structure which would support rotor, power transmission and control systems, and elevates the rotating blades above the earth boundary layer. A successful design should ensure safe, efficient and economic design for the whole wind turbine system. It should provide easy construction and easy access for maintenance of the rotor components and sub-components. UHPC materials have been used in various structural applications, such as highway bridge girders. There is no much research about its application in support structures of wind turbines. After meeting the requirements for loads, minimizing cost is the next most important design driver. Here at MIT, Chuang and Professor Ulm developed a new constitutive model for fiber reinforced cementitious composite materials, which is particularly suitable for high performance cementitious composites including UHPC. On the basis of UHPC material model and the load requirements for wind turbines, the objective of this work is to carry out a tentative design of the UHPC support tower for a prototype wind turbine. Two tube-type cross sections are examined. The 3-d analysis reveals a sufficient flexural performance of the UHPC support tower when subjected to the extreme wind loads. Since this work only focuses on the extreme wind load case, other load cases, such as aerodynamic and operational cases, should be considered before it can be safely employed. Thesis Supervisor: Franz-Josef Ulm Title: Professor of Civil and Environmental Engineering Thesis Reader: Jerome Connor Title: Professor of Civil and Environmental Engineering