A technique for coupled thermomechanical response measurement using infrared thermography and digital image correlation (TDIC)

An integrated infrared thermography and 3-D digital image correlation (TDIC) technique has been developed which allows for simultaneous measurement of spatial and temporal distributions of temperatures and displacements. For this, a novel technique was developed to calibrate the IR thermal cameras with a stereo-vision digital image correlation (DIC) system using the standard pin-hole stereo calibration model. This method fuses thermal and displacement information and compensates for the difference in camera resolutions. Several high temperature black and white paints were evaluated to determine their characteristics including the temperature-dependent emissivity of each paint, the mixed emissivity of both paints in the speckle pattern, and optical thickness. The advantages of evaluating linked full-field temperatures and strain measurements through the TDIC technique are demonstrated through measurements obtained on an E-glass/vinyl ester/balsa wood sandwich composite subjected to simultaneous one-sided heating and compressive loading.