An anisotropic elastic‐decohesive constitutive relation for sea ice

• Published in: International Journal for Numerical and Analytical Methods in Geomechanics
• Main Authors: Tran, Han D., Sulsky, Deborah L., Schreyer, Howard L.
• Other Authors: National Science Foundation
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2015
• Subjects: Arctic; Sea ice
• Online Access: http://dx.doi.org/10.1002/nag.2354; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fnag.2354; https://onlinelibrary.wiley.com/doi/pdf/10.1002/nag.2354

Summary Thermodynamic growth or melt and mechanical redistribution due to lead opening or ridge formation shape the thickness distribution of the Arctic ice cover and impact the overall strength of pack ice. Specifically, the deformation and strength of ice are not isotropic but vary with the thickness and lead orientation. To reflect these facts, we develop an anisotropic, elastic‐decohesive constitutive model for sea ice together with a model to describe an oriented, ice thickness distribution. The tight connection between the mechanical response and the thickness distribution is an improvement over a previous model that only depended on the average ice thickness. The model describes mechanical responses anisotropically in both the elastic and failure regimes. In the elastic regime, the constitutive relation implicitly reflects strong and weak directions of the pack ice depending on the distribution of thin ice (including open water) and thicker ice (e.g., multi‐year ice or ridges). In the failure regime, the model predicts both failure initiation and the lead orientation. Evolution from initial failure to complete failure when traction‐free crack surfaces are formed is also modeled. Crack or lead width is determined during the evolution. Various examples of failure surfaces are presented to describe the behavior of modeled ice when the thickness distribution varies. The model predictions are also illustrated and compared with previous modeling efforts by examining regions of ice under idealized loading. Copyright © 2015 John Wiley & Sons, Ltd.