The Effect of Tensile Strength in the Arctic Ice Pack
The ice pack covering northern seas is composed of an aggregate of thick ridged and rafted ice, undeformed ice, and open water. Existing ice-ocean models of the Arctic ice pack are large-scale continuum models that use a plastic yield surface to characterize the constitutive behavior of the pack. An alternative approach, which captures far more detail, is to explicitly model the ice parcels that make up the ice pack. To this end a granular model of the central Arctic ice pack has been developed. In the granular model each floe has its own ice thickness distribution. Deformation causes leads to open or ridges to form between floes. The granular sea ice model was used to simulate a range of deformation states from uniform convergence to uniform divergence Two sets of simulations were performed. In the first set the joints between neighboring floes were unfrozen and hence unable to support tensile forces, while in the second set the joints were frozen. Stresses in the simulations were calculated in three ways and compared. Yield surfaces constructed from the results of the simulations clearly demonstrate the effects of the tensile strength between floes. The difference in the yield curves is shown to be related to a qualitative difference in the deformation patterns in the model pack. Lastly the discussion looks at the differences between the global stress state in the model ice pack and the stress state in the individual floes.
KeywordsBoundary Element Method Yield Surface Yield Curve Thickness Distribution Pure Shear
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- Hibler, W.D., III, 1986. Ice dynamics, in The Geophysics of Sea Ice, edited by N. Untersteiner, 577–640, Plenum, New York.Google Scholar
- Pritchard, R.S. 1981. Mechanical behavior of pack ice, in Mechanics of Structured Media, Part A, edited by A.P.S. Selvaduri, Elsevier, Amsterdam, 371–405.Google Scholar