Lagrangian methods for modeling compressive failure in sea ice across scales
Abstract
The understanding of the mechanical interaction between ice floes in the polar sea-ice packs is crucial for modeling ice-cover dynamics. Here we study the rheological behavior during compression of idealized ice-floes, modeled with a high-resolution Lagrangian method. The ice floes consist of many particles, interacting through beam theory and elastic-frictional mechanics. The compressive experiments contain distinct elastic and plastic deformation stages. Elastic and reversible deformation offers significant resistance to compression before the ice floes yield to brittle failure and create pressure ridges with Coulomb-frictional sliding between broken ice-floe parts. Importantly, the compressive resistance is low after plastic failure occurs and ridge building is initiated, causing ridge building to naturally localize. The observed behavior of compressive strain weakening contrasts the typical approaches to sea-ice modeling, where sea-ice thickness dictates compressive strength alone regardless of mechanical state. We parameterize the observed behavior under compression into a larger scale discrete-element model with particles of ice-floe size, and show that the susceptibility to ridge and compressive mechanics strongly affect bulk mechanics and strain distribution under compression and shear.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.C33B..07D
- Keywords:
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- 0750 Sea ice;
- CRYOSPHEREDE: 0766 Thermodynamics;
- CRYOSPHEREDE: 0770 Properties;
- CRYOSPHEREDE: 0774 Dynamics;
- CRYOSPHERE