High resolution spatiotemporal DIC based on coupling of high-speed and low-speed cameras

To achieve high spatiotemporal resolution in measuring deformation fields during rock fracture processes, a global multiview spatiotemporal digital image correlation (G-M-ST-DIC) framework is proposed to integrate data from a hybrid experimental optical system. G-M-ST-DIC integrates the high temporal resolution provided by the high-speed camera with the high spatial resolution of the low-speed camera, thereby significantly improving both temporal and spatial resolutions of kinematic measurements. Additionally, denoising and correcting for brightness and contrast variations reduced the displacement uncertainty by 41% and 32%, respectively. The method is validated with a granite semi-circular bending (SCB) experiment. The results indicate that during the non-propagation stage, displacement increments increased linearly over time, whereas during crack propagation, the displacement increments increased nonlinearly with time.