Combined thermoelastic stress analysis and digital image correlation with a single infrared camera

Abstract

A novel methodology simultaneously combining thermoelastic stress analysis (TSA) and digital image correlation (DIC) with a single infrared camera is presented. DIC is an optical method to determine deformation by image tracking with strains determined via differentiation. TSA is a non-contact measurement technique that provides the full-field stress directly using measured temperature changes. The combination of the two techniques improves the resolution and accuracy of TSA results by correcting for sample motion and distortion during loading. Illustrative examples, including an aluminium alloy plate with an edge crack and a nylon plate with a hole under tension, demonstrate the combined method which simultaneously measures stress and displacement.