A Maxwell elasto-brittle rheology for sea ice modelling
A new rheological model is developed that builds on an elasto-brittle (EB) framework used for sea ice and rock mechanics, with the intent of representing both the small elastic deformations associated with fracturing processes and the larger deformations occurring along the faults/leads once the mat...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-07-01
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| Series: | The Cryosphere |
| Online Access: | http://www.the-cryosphere.net/10/1339/2016/tc-10-1339-2016.pdf |
| Summary: | A new rheological model is developed that builds on an elasto-brittle (EB)
framework used for sea ice and rock mechanics, with the intent of
representing both the small elastic deformations associated with fracturing
processes and the larger deformations occurring along the faults/leads once
the material is highly damaged and fragmented. A viscous-like relaxation term
is added to the linear-elastic constitutive law together with an effective
viscosity that evolves according to the local level of damage of the
material, like its elastic modulus. The coupling between the level of damage
and both mechanical parameters is such that within an undamaged ice cover the
viscosity is infinitely large and deformations are strictly elastic, while
along highly damaged zones the elastic modulus vanishes and most of the
stress is dissipated through permanent deformations. A healing mechanism is
also introduced, counterbalancing the effects of damaging over large
timescales. In this new model, named Maxwell-EB after the Maxwell rheology,
the irreversible and reversible deformations are solved for simultaneously;
hence drift velocities are defined naturally. First idealized simulations
without advection show that the model reproduces the main characteristics of
sea ice mechanics and deformation: strain localization, anisotropy,
intermittency and associated scaling laws. |
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| ISSN: | 1994-0416 1994-0424 |