Refined Delamination Factor Failure Characterization of Composite Wind Turbine Blade

Wind turbines are used to convert the kinetic energy of wind into useful power. The wind turbine blades are fabricated using glass fiber-reinforced composite materials. Wind turbine blades are complex section. In order to improve the strength of the blades under varying loading conditions, spars are embedded in it. The spars are fastened with the composite shells of the blades using bolted connections. In order to affect this fastening, holes of appropriate size were drilled in the composite laminates. Delamination is the major failure in composite blades which is induced during drilling. Delamination is quantitatively measured using digital means. A comparison between the conventional (F-D) and adjusted (F-DA) delamination factors is presented. In order to effectively quantify the delamination, refined delamination factor (F-DR) is proposed. It is found that the proposed F-DR predicts the failure in a better manner when compared with predictive capabilities of F-D as well as F-DA.