Sea Ice Fracture and Friction
The fracture and friction of sea ice are discussed and comparisons made with laboratory-grown freshwater ice. The unusual mechanical properties of sea ice, the independence of shear fracture stress on normal stress and the shear fault angle that tends to 45°, observed over a wide range of conditions, suggest that it is inappropriate to apply Coulomb fracture theory generally to sea ice. Direct and inferred microcrack statistics suggest that rock mechanics microcracks models are also inappropriate for ice. Instead it is proposed that a slip-weakening model can capture the essential mechanical properties of ice in shear, including the transition from brittle to ductile behaviour with increasing normal stress and temperature, and the transition from stable frictional sliding to stick-slip behaviour, necessary for modelling sea ice dynamics.
KeywordsAcoustic Emission Shear Fracture Triaxial Test Wing Crack Shear Fault
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