On the Scale Dependence of Cracking Resistance of Structured Solids (on the Example of Marine Ice Cover)

The ice sheet is characterized by the development of fracture structures on a local and regional scale with the participation of fracture processes that occur at different scales, differing from each other by several orders of magnitude. The analysis shows that it is possible to distinguish a class of materials, which, in particular, include sea ice and other granular and structured materials (gypsum, concrete, paraffin, etc.), the effective fracture toughness of which during brittle fracture is affected by a large-scale factor, the role of which a gradient of external stresses appears. A model of this phenomenon is proposed for situations associated with variations in the local stress gradient with a change in the scale of the fracture region. Using the example of sea ice cover, we estimated the impact of the effect on the destruction scenarios of structured media.