A Study on the Uniaxial Tensile and Compressive Mechanical Testing Methods of Ice Specimens Based on the Digital Image Correlation (DIC) Technique

This study introduced the Digital Image Correlation (DIC) technique into the axial tensile and compression tests of ice materials. The surface strain distribution measured by DIC was compared with experimental phenomena to verify the accuracy of DIC measurement technology. Additionally, the strain data obtained from DIC were used to correct the stress–strain rate curves of ice materials under axial tension and compression, as measured by the universal testing machine. The study found that the constitutive relationship of a type of ice material under tension and compression can be fitted to a bi-linear model. After correction, the bi-linear two-stage moduli of the ice specimens frozen at −30 °C during tensile testing were approximately E¯1 = 687.50 MPa and E¯2 = 1.12 GPa; During compression, the bi-linear two-stage moduli are approximately E¯1′ = 1.521 GPa and E¯2′ = 7.734 GPa. The above research results are similar to those of previous studies and have a high degree of credibility. The mechanical properties of ice materials were found to be more stable at a freezing temperature of −30 °C compared to −10 °C. When microcracks form in ice materials under load, these cracks may refreeze internally, leading to viscoelastic behavior in the early stages of loading.