24. Thermoelastic Measurement Techniques Enabled by Self-reference

Until recently thermoelastic stress analysis (TSA) imaging required correlation between an electronic signal related to the stress in a target structure, and the thermal signal acquired in successive IR images. With the implementation of a new method dubbed “self-reference” the requirement for the electronic signal has been eliminated. In the self-reference modality, correlation is made between the temporal variation in the signal from a region-of-interest in the image, to each of the pixels in the image. This simple change of correlation parameters has had a dramatic effect on the applicability of TSA and the ease of use of TSA instruments. A review of a range of applications in the light of this change indicates a new level of applicability of the TSA technique for stress measurement.