Comparison of infrared thermography and miniature Deltatron accelerometer sensors in the measurement of structural vibration characteristics

Abstract

This paper investigates the comparison of infrared thermography (IRT) and miniature Deltatron accelerometer sensors in measuring structural vibration characteristics in terms of frequency and displacement, given that of age IRT has fully grown for temperature condition monitoring. In addition, IRT has been extensively applied in non-destructive techniques for evaluation of surface cracks through the observation of thermal imaging of vibration-induced crack frictional heat generation. Therefore, in order to conduct this study, both single and dual cantilever beam-like structures (AISI 304 steel) coupled with a slipping frictional rod (lacing wire) were subjected to forced excitations with an infrared camera capturing the thermal profile emanating from beam-lacing wire frictional interface. Concurrently, miniature Deltatron accelerometer sensors were attached to the beam surface next to the frictional interface focused by IR camera. The thermally analyst vibration characteristics parameters were compared against those acquired by accelerometers. The comparison of results exhibited a maximum relative difference of 0.28% and 14.88% for frequencies and displacements, respectively. This shows that IRT is more reliable in measuring structural vibration frequency than displacements. The finding is particularly useful in overcoming many limitations inherent in some of the current vibration measuring techniques such strain gauges failure due to fatigue.