Effects of Structure Nonlinear on FullScale Wind Turbine Blade Static Test

Abstract:

The effects of structure nonlinear on fullscale wind turbine blade static test were studied in this paper. First, the relationship between bending moment, strain, stiffness and deflection were theoretically analyzed. Then, fullscale blade was mounted on the test bench for extreme load static test. As the blade was deformed during the loading process, the loading angle, the radial, and tangential deflection of the blade were changed because of the blade structure nonlinear and torsional coupling. The loading force angle and arm were measured by using the triangular method. The strain gauges installed in the different section of the blade were used to measure the local strain on the blade. The results show that, compared with FEM target value, the maximum deviation of stiffness in 4 m away root during static test in flapwise direction is 48% and the maximum deviation of stiffness in 23 m away root in edgewise direction is 29%. The experimental results provide accurate stiffness data for numerical model of wind turbine to load calculations.