Broadband signal reconstruction for SHM: An experimental and numerical time reversal methodology. (June 2021)

• Record Type: Journal Article
• Authors: Falcetelli, Francesco; Venturini, Nicolas; Romero, Maria Barroso; Martinez, Marcias J; Pant, Shashank; Troiani, Enrico
• Is Part Of: Journal of intelligent material systems and structures. Volume 32:Number 10(2021)
• Page Start: 1043
• Page End: 1058
• Publication Date: 2021-06
• Subjects: Structural health monitoring -- Lamb waves -- time reversal -- acoustic emission -- piezoelectric transducer; Smart materials -- Periodicals; Intelligent control systems -- Periodicals; Artificial intelligence -- Periodicals; Matériaux intelligents -- Périodiques; Commande intelligente -- Périodiques; Intelligence artificielle -- Périodiques; 620.11
• DOI: 10.1177/1045389X20972474
• Languages: English
• ISSNs: 1045-389X

Abstract

Structural Health Monitoring (SHM) aims to shift aircraft maintenance from a time-based to a condition-based approach. Within all the SHM techniques, Acoustic Emission (AE) allows for the monitoring of large areas by analyzing Lamb waves propagating in plate like structures. In this study, the authors proposed a Time Reversal (TR) methodology with the aim of reconstructing an original and unaltered signal from an AE event. Although the TR method has been applied in Narrow-Band (NwB) signal reconstruction, it fails when a Broad-Band (BdB) signal, such as a real AE event, is present. Therefore, a novel methodology based on the use of a Frequencies Compensation Transfer Function (FCTF), which is capable of reconstructing both NwB and real BdB signals, is presented. The study was carried out experimentally using several sensor layouts and materials with two different AE sources: (i) a Numerically Built Broadband (NBB) signal, (ii) a Pencil Lead Break (PLB). The results were validated numerically using Abaqus/CAE TM with the implementation of absorbing boundaries to minimize edge reflections.