Design optimization of whiffletree systems for wind turbine blade testing

Yeniceli, Süleyman Cem
In this thesis, the design optimization of a whiffletree system, which is used to simulate the loads for a selected design load case by applying discrete test loads on a wind turbine blade, is performed. Firstly, distributed design loads are calculated for the selected load case by using Microsoft (MS) EXCEL. Then, the test load optimization is performed with the Solver Add-In of the MS EXCEL to find the optimum locations of the load saddles which give the best moment distribution along the blade span according to the design loads. To simplify and generalize the test load optimization process, a tool with Graphical User Interface (GUI) is prepared with MATLAB which has built-in optimization algorithms. Genetic algorithm and gradient based optimization algorithms of MATLAB are used in hybrid form to determine the saddle locations and associated force values for test load optimization. To demonstrate the winch loading method option, which is different from the whiffletree system, and to apply developed optimization tool in a much longer blade, design loads for the NREL offshore 5-MW baseline wind turbine blade is calculated and test load optimization is performed. Finally, the whiffletree is designed to connect the primary load introduction apparatus with the saddles according to the saddle locations obtained by optimization. Results show that the developed optimization tool which makes use of the built-in optimization algorithms in MATLAB successfully determines the optimum load introduction points and associated force values both for the Whiffletree system and winch loading case.
Citation Formats
S. C. Yeniceli, “Design optimization of whiffletree systems for wind turbine blade testing,” M.S. - Master of Science, Middle East Technical University, 2014.