Data for: Condition monitoring system for in situ crack detection based on thermal emissions

The advent of packaged infra-red (IR) bolometer detectors has led to
thermography-based techniques becoming popular for non-destructive
evaluation of aerospace structures. These packaged bolometers are
relatively compact and cost about 10% the price of high-resolution IR
photovoltaic effect detectors. In this work, a condition monitoring system
for in situ crack detection has been presented which utilises an original
equipment manufacturer (OEM) microbolometer detector. The proposed system
cost approximately 1% the price of a state-of-the-art photovoltaic effect
detector system and has the potential to transform the use of IR imaging
for condition monitoring in the aerospace industry and elsewhere. The
proposed system performs crack detection based on the principles of
thermoelastic stress analysis (TSA), which is a well-established
non-destructive thermography technique. Proof-of-concept lab tests were
performed on open-hole aluminium specimens to compare the performance of
the proposed system against an IR photovoltaic effect detector system and
demonstrate its potential application for in situ crack detection in
industrial environments. It was demonstrated that crack detection is
possible from loading waveform signals with 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.