To improve the defect detectability of Lamb wave inspection systems, application of non-linear signal processing was investigated. The approach is based on a Warped Frequency Transform (WFT) to compensate the dispersive behavior of ultrasonic guided waves, followed by a Wigner-Ville time-frequency analysis and the Hough Transform to further improve localization accuracy. As a result, an automatic detection procedure to locate defect-induced reflections was demonstrated and successfully tested by analyzing numerically simulated Lamb waves propagating in an aluminum plate. The proposed method is suitable for defect detection and can be easily implemented for real application to structural health monitoring.
A. Perelli, L. De Marchi, E. Baravelli, A. Marzani, N. Speciale (2011). Warped-wigner-hough transformation of lamb waves for automatic defect detection. IEEE UFFC Society [10.1109/ULTSYM.2011.0266].
Warped-wigner-hough transformation of lamb waves for automatic defect detection
PERELLI, ALESSANDRO;DE MARCHI, LUCA;BARAVELLI, EMANUELE;MARZANI, ALESSANDRO;SPECIALE, NICOLO'ATTILIO
2011
Abstract
To improve the defect detectability of Lamb wave inspection systems, application of non-linear signal processing was investigated. The approach is based on a Warped Frequency Transform (WFT) to compensate the dispersive behavior of ultrasonic guided waves, followed by a Wigner-Ville time-frequency analysis and the Hough Transform to further improve localization accuracy. As a result, an automatic detection procedure to locate defect-induced reflections was demonstrated and successfully tested by analyzing numerically simulated Lamb waves propagating in an aluminum plate. The proposed method is suitable for defect detection and can be easily implemented for real application to structural health monitoring.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.