Résumé | Results of laboratory and field tests on the dynamic friction factor between ice (freshwater, urea-doped, and granular or columnar sea ice) and bare or Inerta-coated steel plates of various roughness averages are presented. Laboratory tests were made at three air temperatures, T = -15, -9, and -2 C, with either the ice sample towed over the test plate or a plate sample towed over the ice sheet. All field tests were made at T = -2 C to 0 C. The maximum test velocity was 30 cm/s, and the normal pressure was of the order of 10 kPa. From the test results it is concluded that viscous shear in the meltwater layer between ice and test plate may dominate when the test plate is very smooth, as proposed by Oksanen in his analytical model, but when the material roughness increases, mechanical shear of the ice crystals dominates. |
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