Based on the numerical simulation of various damage conditions of the small fan blades in the stalling and running states, the modal analysis was carried out to study the method to identify and locate the blade damage, and the author calculated the weighted flexibility curvature index to establish Fitting function of weighted flexibility curvature value and stiffness damage value. The results are as follows: firstly, whether the blade is damaged can be judged by the change of natural frequency. Secondly, regardless of the blade damage, as the blade speed increases, its natural frequency will increase. If the weighted flexibility curvature value mutates at the damage location, there will be a peak protrusion, and along with the increasing of the degree of damage, the peak protrusion becomes more obvious. At the same time, the fitting function proposed in this paper has minor errors and high reliability, which can locate the damage of the blade and quantify the degree of damage.
Key words
wind turbines /
blades /
numerical simulation /
modal analysis /
weighted flexibility curvature value
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