A new and versatile experimental stress analysis technique has recently been developed, based on the measurement of the infra-red radiation emitted from the surface of a body as a result of temperature changes caused by cyclic loading within the elastic range (i.e. the thermoelastic effect). The theory is outlined and the apparatus (referred to as the SPATE equipment) is described. A number of applications are described to illustrate the principal characteristics of the technique which is now regarded as a valuable new approach in the stress analysis and design assessment of a wide range of engineering components and structures. Possible future developments in this area are outlined.
"An Appraisal Of A New Infra-Red Based Stress Analysis Technique", Proc. SPIE 0590, Infrared Technology and Applications, (1 May 1986); doi: 10.1117/12.951993; https://doi.org/10.1117/12.951993