Ice-structure interactions produce numerous, short-lived high pressure zones which transfer the majority of the load to the structure. Ice indentation tests have been used to observe the fluctuations in surface temperature at these zones. Previous investigations have shown that temperature fluctuates inversely to the applied load during cyclic loading. These fluctuations are believed to be due to rapid melting and refreezing cycles in the high pressure zones.
A recent series of small-scale indentation tests investigated surface temperature fluctuations for indentor speeds at three orders of magnitude (0.21 mm/s to 21 mm/s). Freshwater granular ice specimens were grown in cylindrical steel moulds using seed ice and distilled water. A 70 mm diameter indentor with a radius of curvature of 89.6 mm was indented into the ice to depths between 10 and 15 mm. Seven thermocouples were installed in the indentor and made flush with its surface. These were used to measure the surface temperature of the ice during indentation. All tests took place at −10 degrees.
Notable changes in temperature response were observed with changing speed. A steady increase in temperature was observed during low speed tests. Medium speeds lead to fluctuations in temperature due to the presence of spalling and cyclic loading that is consistent with the results of others. Some evidence of the inverse relationship between load and temperature can be observed in the highest speed tests, but the thermocouples sampling frequency was too low to accurately respond to high frequency loading and could not provide clear results.