12th International Conference on Offshore Mechanics and Arctic Engineering, 20-24 June 1993, Glasgow, Scotland
Indentation tests were conducted using a segmented indentor at different indentation velocities against freshwater ice. To determine the nature of ice failure at different rates, the effective pressure was measured on each segment of the indentor. The variation of pressure on each segment of the indentor was simultaneous at low-velocity indentation, whereas it was random during high-velocity indentation. Spectral and correlation plots of the data show that the degree of randomness in the measured pressure signal increased with an increase in indentation velocity. Plots of the mean, the maximum and the standard deviation of the measured pressure ar given with respect to the indentation velocity and the aspect ratio. For brittle ice failure, the actual contact of the ice with the indentor is over many small contiguous zones where brittle flaking originates because of high pressure. The trends of decreasing standard deviation with increasing indentation velocity and increasing aspect ratio are attributed to a decrease in the size and an increase in the number of the failure zones, respectively.