Detecting damages for wind turbine blades based on Chebyshev polynomial approximation and uniform load surface curvature

Wind turbine blades are among the most critical components of a wind turbine. Cracking is the most prevalent type of the WT blades damage, making it essential to develop methods for early detection and precise assessment of crack locations and severity. This paper proposes a novel method based on uniform load surface (ULS) curvature variation for determining the damage location in wind turbine blades. The Chebyshev polynomial is utilized instead of the central difference method to calculate ULS curvature. This method only needs the first-order natural frequency of the WT blade to detect the damage of the WT blade, and the numerical simulation results show that its calculation accuracy has low requirements on the number of measurement points. An experimental platform was established to collect modal data and a model updating technique was employed to adjust the simulation model parameters. Consequently, this method enhances the traditional modal curvature approach, offering a more comprehensive and reliable technique for structural health monitoring of wind turbine blades.