Nam Seo GOO, Xiongjie CHE
DOI Number: XXX-YYY-ZZZ
Conference number: HiSST2024-00215
A heat shield called the thermal protection system (TPS) is an important structure in high-speed vehicle as it protects the vehicle from aerodynamic heating. In order to study the TPS, it is particularly important to measure the deformation of structures in high temperature environments. This study presents an improved method for high-temperature measurement using the digital image correlation (DIC) technique and infrared heater, with a focus on the effects of speckle patterns and mitigation of heat haze effects. The effect of speckle pattern on the DIC measurement has been studied well at room temperature, but high-temperature measurement studies did not report such effects so far. And we also found that the commonly used methods to reduce the heat haze effect could produce incorrect results. So, we studied how to determine the proper size of the speckle pattern under a high-temperature environment. And then we invented the reduction method of the heat haze effect. Finally, we mitigated image saturation using a short-wavelength bandpass filter with blue light illumination to avoid the blackbody radiation from the heated structure, a standard procedure for high-temperature DIC deformation measurement. As proof of our developed experimental method, the deformation of stainless steel 304 specimens was measured from 25 ℃ to 800 ℃ successfully, which means this method can be applied to the research and development of thermal protection systems in the aerospace field.