Signal processing for damage detection using two different array transducers

Faysal El Youbi (1, 2) , Sébastien Grondel (1, 2) , Jamal Assaad (1, 2)

1 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
2 IEMN-DOAE - Institut d’Électronique, de Microélectronique et de Nanotechnologie - Département Opto-Acousto-Électronique - UMR 8520

This work describes an investigation into the development of a new health monitoring system for aeronautical applications. The health monitoring system is based on the emission and reception of Lamb waves by multi-element piezoelectric transducers (i.e., arrays) bonded to the structure. The emitter array consists of three different elementary bar transducers. These transducers have the same thickness and length but different widths. The receiver array has 32 same elements. This system offers the possibility to understand the nature of the generated waves and to determine the sensitivity of each mode to possible damage. It presents two principal advantages: Firstly, by exciting all elements in phase, it is possible to generate several Lamb modes in the same time. Secondly, the two-dimensional fourier transform (2D-FT) of the received signal can be easily computed. Experimental results concerning an aluminum plate with different hole sizes will be shown. The A0-, S0-, A1-, S1- and S2-modes are generated at the same time. This study shows that the A0 mode seems particularly interesting to detect flaws of this geometrical type.

Mots clés: Lamb waves; Multi-element transducers; 2D-FT; Damage detection

Domaines: Sciences de l'ingénieur [physics]

Faysal El Youbi, Sébastien Grondel, Jamal Assaad. Signal processing for damage detection using two different array transducers. Ultrasonics, 2004, 42, pp.803-806. ⟨10.1016/j.ultras.2004.01.070⟩. ⟨hal-00142003⟩