A thermal emissions-based real-time monitoring system for <i>in situ</i> detection of fatigue cracks



Amjad, K ORCID: 0000-0002-9348-0335, Lambert, P ORCID: 0000-0001-9525-0667, Middleton, CA ORCID: 0000-0001-9488-9717, Greene, RJ ORCID: 0000-0002-5373-0598 and Patterson, EA ORCID: 0000-0003-4397-2160
(2022) A thermal emissions-based real-time monitoring system for <i>in situ</i> detection of fatigue cracks. PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 478 (2266). 20210796-.

[img] Text
rspa.2021.0796.pdf - Published version

Download (2MB) | Preview

Abstract

<jats:p> The advent of packaged infrared (IR) bolometers has led to thermography-based techniques becoming popular for non-destructive evaluation of aerospace structures. In this work, a real-time monitoring system for <jats:italic>in situ</jats:italic> crack detection has been presented which uses an original equipment manufacturer microbolometer. The system costs one-tenth the price of a packaged bolometer and has the potential to transform the use of IR imaging for condition and structural health monitoring in the aerospace industry and elsewhere. A computer, consisting of a single circuit board with dimensions comparable to a credit card, has been integrated into the system for real-time, on-board data processing. Crack detection has been performed based on the principles of thermoelastic stress analysis (TSA). Proof-of-concept laboratory tests were performed on open-hole aluminium specimens to compare the performance of the proposed system against a state-of-the-art cooled IR photovoltaic effect detector. It was demonstrated that cracks as small as 1 mm in length can be detected with loading frequencies as low as 0.3 Hz. This represents a significant advance in the viability of TSA-based crack detection in large-scale structural tests where loading frequencies are usually lower than 1 Hz. </jats:p>

Item Type: Article
Uncontrolled Keywords: condition monitoring, fatigue, crack monitoring, thermoelastic stress analysis, infrared thermography, microbolometer
Depositing User: Symplectic Admin
Date Deposited: 05 Oct 2022 07:18
Last Modified: 14 Mar 2024 18:52
DOI: 10.1098/rspa.2021.0796
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3165201