Material Compression Tests on Rigid Insulation Tiles at Elevated Temperatures with Digital Image Correlation

The mechanical properties of rigid insulation tile (RIT) materials at elevated temperatures (700 ~ 1000 ℃) were studied through compression tests and the digital image correlation (DIC) method. To reduce measurement error in a thermal environment, an image gradient zero-mean normalized cross-correlation algorithm (ZNCCGI) was added to the DIC algorithm. The DIC algorithm was verified via RIT material mechanical tests at room temperature. Furthermore, the compressive stress–strain curves and Young's modulus of RIT materials at elevated temperatures were obtained. The experimental results show that the Young's modulus of RIT materials significantly increased at 800 ℃. Moreover, the compressive yield strength was significantly improved at 800 ℃, which resulted in a random distribution of ceramic fibers and viscous flow deformation at elevated temperatures. Scanning electron microscope analysis demonstrated that the compressive damage occurs due to the breaking of ceramic fibers.