High-temperature digital image correlation techniques for full-field strain and crack length measurement on ceramics at 1200°C: Optimization of speckle pattern and uncertainty assessment

High-temperature mechanical tests coupled with Digital Image Correlation (DIC) on ceramics which exhibit rather low level of strain require to overcome extreme experimental conditions that usually can reduce significantly measurement accuracy. Thermal resistance speckle pattern, black body radiation and heat haze are three main concerns, should thus be taken into account while designing a high-temperature image acquisition setup. In this aim, an procedure has been specifically designed in order minimize the above-mentioned disturbances. The objective study is select suitable resistant pattern for characterization at 1200 °C (or above) refractory ceramics. Most tested patterns were performed white alumina adhesive dark ceramic grains (silicon carbide or brown fused alumina). Different grain sizes silicon tested. At first, different compared terms DIC uncertainty by discussing features, some parameters two pre-treatments (low pass filter, size reduction). Then, these analyse fracture behaviour refractories through Brazilian test. An enhanced digital correlation technique (2P-DIC), dedicated monitor behaviour, applied evolution crack length. best representation progression achieved sample surface covered fine SiC powder ranging from 50 100 µm. It then possible compare between 20 show exhibits more branching comparison room temperature.