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Student Seminar Series

Department of Atmospheric & Oceanic Sciences

presents

a talk by

Mathieu Plante
PhD student

Improving the damage parameterization of the Maxwell Elasto-Brittle rheology to better resolve the orientation of ice fractures

The Maxwell Elasto Brittle (MEB) rheology (Dansereau et al., 2016) is a damage parameterization based rheology that was developed to better represent the fracture of ice. This rheology was implemented in the Lagrangian sea ice model neXtSIM (Rampal et al., 2015), and was shown to adequately represent the statistics of sea ice deformation fields. This new physics governing the fracture of sea ice remains however highly parameterized. In recent years, we implemented the MEB rheology in the Eulerian framework commonly used in the sea ice modelling community. In ideal ice bridge experiments, it was shown that the damage parameterization is unstable under large compression, lacks strain hardening properties and produces angles of fracture that do not follow theory. Here, we use ideal uniaxial compression simulations to identify the origin of these instabilities, to quantify the deviation of the angles of fracture from the theory and to determine the flow rule implied by the damage parameterization. We propose a modification to the parameterization that improves both the model stability and the simulated orientation of the lines of fracture. We however stress that the modifications are yet not tantamount to including a flow rule, such that the type of deformation associated to the ice fracture remains dissociated from the yield parameters.

Wednesday Dec 04/ 2.30 PM/ Room 934 Burnside Hall

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