Abstract | Medium scale ice indentation experiments were performed at Hobson's Choice Ice Island using an indentor outfitted with a window and video camera so that the ice behavior could be observed in situ. The video images revealed high pressure zones of relatively intact ice, surrounded by crushed ice, that bore most of the load. The load data exhibited a sawtooth pattern which the video records showed was due to spalling of ice away from the contact area. This determined the shape of the high pressure zones. All damage to the ice, and actual movement of the indentor into the ice, occurred during the sharp drops in the sawtooth load data. Pressures in the high pressure zones, determined from the visual records and load data, agreed with the highest pressures measured by sensors on the indentor face (40 to 60 MPa range). |
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