The Feasibility of Structural Health Monitoring Using the Fundamental Shear Horizontal Guided Wave in a Thin Aluminum Plate
Department of Mechanical Engineering, Universidade Federal Fluminense, Niteróy 24220-900, Brazil
Department of Mechanical Engineering, École de Technologie Supérieure, Montreal, QC H3C 1K3, Canada
Author to whom correspondence should be addressed.
Academic Editors: Victor Giurgiutiu and Shenfang Yuan
Materials 2017, 10(5), 551; https://doi.org/10.3390/ma10050551
Received: 11 April 2017 / Revised: 9 May 2017 / Accepted: 17 May 2017 / Published: 19 May 2017
(This article belongs to the Special Issue Structural Health Monitoring for Aerospace Applications 2017)
Structural health monitoring (SHM) is emerging as an essential tool for constant monitoring of safety-critical engineering components. Ultrasonic guided waves stand out because of their ability to propagate over long distances and because they can offer good estimates of location, severity, and type of damage. The unique properties of the fundamental shear horizontal guided wave (SH0) mode have recently generated great interest among the SHM community. The aim of this paper is to demonstrate the feasibility of omnidirectional SH0 SHM in a thin aluminum plate using a three-transducer sparse array. Descriptions of the transducer, the finite element model, and the imaging algorithm are presented. The image localization maps show a good agreement between the simulations and experimental results. The SH0 SHM method proposed in this paper is shown to have a high resolution and to be able to locate defects within 5% of the true location. The short input signal as well the non-dispersive nature of SH0 leads to high resolution in the reconstructed images. The defect diameter estimated using the full width at half maximum was 10 mm or twice the size of the true diameter.