Full Scale Structural Experimental Investigation of an E-Glass/Epoxy Composite Wind Turbine Blade

Abstract

A structural test of a new wind turbine rotor blade was performed to evaluate design uncertainties due to material defects, analytical assumptions and production process, and quantify their effect on its structural integrity. In the full-scale static strength test, the measuring parameters were the blade weight, location of centre of gravity, in-plane strains, deflections and failure loads. Performing a three-point bending test of the full-scale (size) blade simulated the aerodynamic load experienced by the rotor blade. Analytical predictions for mass of the blade, centre of gravity location, blade tip deflection and the first flap-wise natural frequency were in good agreement with the measured values. The difference was less than 4%, indicating that the blade response was accurately modelled by a linear analysis. The axial strain of the blade skin was also measured at several blade stations: 5.56 m, 11.59 m and 13.43 m at an applied load of 20%, 40%, 60%, 80% and 100% of the maximum design load. Acceptable agreement was achieved between experimental and theoretical strain results, using the Tsai-Wu failure criterion.