The Estimation Of The Lamb Wave Phase Velocity Dispersion Curves Base On K-Means Clustering Algorithm

Lamb waves are widely used in the localization and quantification of structural damage for plate-type structure. The propagation velocity and dispersion characteristics of Lamb waves are very important calculation parameters. The method to estimate the dispersion curves of Lamb waves is proposed based on K-means clustering algorithm. Three piezoelectric transducers with different center frequencies experimentally transmit the Lamb wave signals, and laser vibrometer is used to receive signals at different intervals in the direction of wave propagation. The phase velocity of lamb waves is estimated by many pairs of adjacent signals peaks. Use Euclidean distance as the index of data evaluation to find the data center, which is the phase velocity to be solved. And the dispersion curves are further estimated and inverted. The proposed method has been experimentally verified in isotropic-aluminum plate. The relative error of the actual phase velocity of lamb waves compared with all measured clustering centers is less than 1%, and the overall average relative error is less than 0.4%.