Application of synchrosqueezed wavelet transforms in Lamb wave based structural health monitoring of wind turbine blades

The wind turbines are deployed in harsh natural environments and operate at high loads. In this situation, the wind turbine blades arc easily damaged. Active Lamb wave based structure health monitoring technology is a proper way to ensure the safe operation of wind turbines. However, due to the complex propagation of Lamb waves in the wind turbine blades, it's usually hard to analyze the responses and to extract the characteristic parameters. Synchrosqueezed wavelet transforms is a one of the new time-frequency domain analysis methods. It is based on wavelet transform and synchrosqueezed compression to extract wavelet ridges, which makes the time-frequency expression of harmonic signals clearer. In this paper, the application of synchrosqueezed wavelet transforms are introduced based on the analysis of the mechanism of active Lamb wave based structural health monitoring. In the experiments, wavelet transform and synchrosqueezed wavelet transforms was performed on a series of responses, and the effectiveness of synchrosqueezed wavelet transforms in active Lamb wave based structural health monitoring is verified by comparison.