Abstract:
Infrared thermography (IRT) has matured and is now widely accepted as a condition monitoring tool
where temperature is measured in a non-contact way. Since the late 1970s, it has been extensively used
in vibrothermography (Sonic IR) non-destructive technique for the evaluation of surface cracks through
the observation of thermal imaging of the vibration-induced crack heat generation. However, it has not
received research attention on prediction of structural vibration behaviour, hence; the concept to date is
not understood. Therefore, this paper explores its ability to fill the existing knowledge gap. To achieve
this, two cantilever beam-like structures couple with a friction rod subjected to a forced excitations while
infrared cameras capturing the thermal images on the friction interfaces. The analysed frictional temperature
evolution using the Matlab Fast Fourier Transform (FFT) algorithm and the use of the heat conduction
equation in conjunction with a finite difference approach successfully identifies the structural
vibration characteristics; with maximum error of 0.28% and 20.71% for frequencies and displacements,
respectively. These findings are particularly useful in overcoming many limitations inherent in some of
the current vibration measuring techniques applied in structural integrity management such as strain
gauge failures due to fatigue.
