Lamb-Wave-Based Multistage Damage Detection Method Using an Active PZT Sensor Network for Large Structures

Abstract

A multistage damage detection method is introduced in this work that uses piezoelectric lead zirconate titanate (PZT) transducers to excite/sense the Lamb wave signals. A continuous wavelet transformation (CWT), based on the Gabor wavelet, is applied to accurately process the complicated wave signals caused by the damage. For a network of transducers, the damage can be detected in one detection cell based on the signals scattered by the damage, and then it can be quantitatively estimated by three detection stages using the outer tangent circle and least-squares methods. First, a single-stage damage detection method is carried out by exciting a transducer at the center of the detection cell to locate the damaged subcell. Then, the corner transducers are excited in the second and third stages of detection to improve the damage detection, especially the size estimation. The method does not require any baseline signal, and it only utilizes the same arrangement of transducers and the same data processing technique in all stages. The results from previous detection stages contribute to the improvement of damage detection in the subsequent stages. Both numerical simulation and experimental evaluation were used to verify that the method can accurately quantify the damage location and size. It was also found that the size of the detection cell plays a vital role in the accuracy of the results in this Lamb-wave-based multistage damage detection method.

Transverse Damage Localization and Quantitative Size Estimation for Composite Laminates Based on Lamb Waves

“…The other reason is that the S 0 mode was better separated from the A 0 mode at longer distance d, and reduced the delay time errors. The recent studies have also provided the similar trends of reduction in error as the distance from the excitation increases for both metallic [38] and composite [48] plates.…”

“…The S 0 mode is preferred for damage detection in majority of research due to its fast propagation velocity and easy identification as compared to the A 0 mode. Furthermore, in different composite layups and along all other propagation directions, the dispersion curves of Lamb waves have the similar property [1], [38]. Therefore, the scattered S 0 mode as the one propagating faster [39], [40], was exclusively considered for the proposed method.…”

Damage Localization of Composites Based on Difference Signal and Lamb Wave Tomography

“…It was inevitable that Lamb wave would be affected by noise in collecting signals. In order to remove the noise in the collection of the response signal, the wavelet transform technique which is known for excellent denoising performance was adopted to filtrate the noise of signals [28,29]. Figure 8 shows the original signal and the denoised signal.…”

Multihelical Lamb Wave Imaging for Pipe-Like Structures Based on a Probabilistic Reconstruction Approach

“…Gao et al combined broadband excitation and pulse compression to locate and assess the damage [28]. Hameed et al applied continuous wavelet transformation and developed the multistage detection scheme to quantify the damage [29]. However, the overlapping phenomenon in helical Lamb wave presents in different forms and the corresponding processing and imaging method need to be investigated.…”