Title
Identifying Defects In Aerospace Composite Sandwich Panels Using High-Definition Distributed Optical Fibre Sensors
Abstract
Automated methods for detecting defects within composite materials are highly desirable in the drive to increase throughput, optimise repair program effectiveness and reduce component replacement. Tap-testing has traditionally been used for detecting defects but does not provide quantitative measurements, requiring secondary techniques such as ultrasound to certify components. This paper reports on an evaluation of the use of a distributed temperature measurement system-high-definition fibre optic sensing (HD-FOS)-to identify and characterise crushed core and disbond defects in carbon fibre reinforced polymer (CFRP)-skin, aluminium-core, sandwich panels. The objective is to identify these defects in a sandwich panel by measuring the heat transfer through the panel thickness. A heater mat is used to rapidly increase the temperature of the panel with the HD-FOS sensor positioned on the top surface, measuring temperature. HD-FOS measurements are made using the Luna optical distributed sensor interrogator (ODISI) 9100 system comprising a sensor fabricated using standard single mode fibre (SMF)-20 of external diameter 250 mu m, including the cladding. Results show that areas in which defects are present modulate thermal conductivity, resulting in a lower surface temperature. The resultant data are analysed to identify the length, width and type of defect. The non-invasive technique is amenable to application in challenging operational settings, offering high-resolution visualisation and defect classification.
Year
DOI
Venue
2020
10.3390/s20236746
SENSORS
Keywords
DocType
Volume
HD-FOS, OFDR, aerospace, thermal analysis
Journal
20
Issue
ISSN
Citations 
23
1424-8220
0
PageRank 
References 
Authors
0.34
0
7
Name
Order
Citations
PageRank
James A. Mills100.34
Andrew Hamilton2414.09
David I. Gillespie300.34
Ivan Andonovic46016.05
Craig Michie5155.78
Kenneth Burnham600.34
christos tachtatzis79114.27