Measurement of crack speed in saline ice using Digital Image Correlation

Crack speed is an important parameter in ice mechanics applications such as crushing and splitting of ice sheets. A wide range of crack speeds, in different types of ice, have been reported in the literature which focused on crack initiation and propagation. In these studies, various methods of studying propagating crack tip location and crack speed have been discussed. In the current work, Digital Image Correlation (DIC) is used to understand crack propagation speed in S2 saline ice. For this, pre-cracked Semi-Circular Bending (SCB) specimens of different sizes were loaded at various loading rates. Propagating crack tip was located using novel technique of cross-correlation between the displacement data and discontinuity functions. Maximum crack speed of approximately 20m/s was recorded in the stable crack propagation regime while minimum 100m/s speed was observed during the unstable crack growth.