Laub, Felix ; Haugwitz, Christoph ; Allevato, Gianni ; Seiler, Julian ; Findeisen, Rolf ; Kupnik, Mario (2023)
Non-contact Lamb wave defect detection based solely on air-coupled ultrasonic phased arrays.
2023 IEEE SENSORS. Vienna, Austria (29.10. - 01.11.2023)
doi: 10.1109/SENSORS56945.2023.10324898
Konferenzveröffentlichung, Bibliographie

Kurzbeschreibung (Abstract)

Air-coupled ultrasonic non-destructive testing (NDT) enables the inspection of composite materials for defects. In this paper, we investigate non-contact defect detection based on Lamb waves by using two dedicated air-coupled ultrasonic phased arrays, i.e. one for transmission and one for reception. The major challenge is the signal detection of the reflected leaky Lamb wave originating from the defect, despite a strong interfering signal, i.e. the direct air-path wave, causing a so-called blind zone. Therefore, we exploit the angular difference of the reflected leaky Lamb wave and the direct air-path wave by applying high-resolution direction of arrival (DoA) estimation algorithms, i.e. MVDR beamformer (Capon) and MUSIC algorithms, as well as image deconvolution methods, i.e. CLEAN and Richardson-Lucy algorithms. First, we assess the signal detection capability by using Monte Carlo simulations considering realistic non-ideal array elements. Second, we validate the simulations by conducting testbed measurements, which show that conventional beamforming (CBF), MVDR and MUSIC are capable of fully air-coupled defect detection, even when the direct air-path wave is impinging. We conclude that the blind zone can be eliminated and show that the MUSIC algorithm excels in highlighting the reflected leaky Lamb wave.

Frage zum Eintrag

Redaktionelle Details anzeigen