Blind single-channel lamb wave mode separation using independent component analysis on time-frequency signal representation

Abstract

Guided waves are widely employed in non-destructive testing, but the presence of dispersion and multiple modes poses a challenge in detecting and separating the received signals, thereby affecting the performance of testing algorithms. Traditional methods for ultrasonic wave mode separation rely on time-frequency transforms, which often require extensive post-processing or the selection of specific frequency points for mode separation. In contrast, this paper introduces a blind separation method that utilizes independent component analysis to facilitate blind single-channel Lamb wave multimode separation. The proposed method demonstrates robust performance even under high noise power levels, while effectively localizing the source energy in the time-frequency domain. Numerical and experimental tests validate the effectiveness of the proposed method, showcasing its ability to successfully separate signals from instantaneous linear mixtures.