Consequently, little or no emphasis has been placed on quantifying the specific physical mechanisms of cracking in ice. Fracture is generally taken for granted in the aforementioned models due in part to the limited amount of relevant studies in the ice literature. Crack initiation and propagation in ice sheets form the basis of many models of ice structure/interaction, the formation of pressure ridges, rubble fields and leads as well as the acoustic emission associated with field-scale deformations of ice. The primary failure mechanism of Arctic ice sheets is fracture.
The important findings of this paper are that: (i) in warm saline ice, extensive local crack-tip damage is accompanied by a limited amount of slow, stable crack extension (n) fracture in cold saline ice is characterized by locally negative K R behavior and (iii) fracture in cold or warm saline ice is characterized by globally positive K R curve behavior. This paper offers the development of a new fracture geometry capable of sustained stable crack growth and the presentation of fracture-resistance curves for saline ice at −25° and −15 C.
The energetic stability criteria of crack growth are examined in saline ice and crack growth is characterized in terms of the fracture-resistance parameter K R. As has been previously observed in cold sea ice and warm or cold fresh-water ice, crack growth occurs in initiation/arrest increments. Crack propagation in saline ice (a model sea ice) is investigated in this study in an attempt to understand the processes of crack growth at one loading rate and two temperatures.
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