Pack ice as a two-dimensional granular plastic: A new constitutive law

Abstract

The purpose of this study is to propose a new constitutive law for pack ice, which is not only capable of simulating the in-plane shear and out-of-plane uniaxial compression, but also capable of avoiding overestimating divergence during shear. The pack ice is treated as a two-dimensional granular plastic, obeying Coulomb's friction law with a maximum principal stress limit. During the out-of-plane uniaxial compression process the flow rule is normal, while during the in-plane shear process the flow rule is coaxial with a linearly varying dilatancy angle describing the divergence. The strength parameterizations are based on thickness and compactness of the pack ice; weakening or hardening can be achieved through advection and redistribution.