Modeling Sea Ice as an Elasto-Plastic Frictional Material

Abstract

Mechanical properties of sea ice are determined by the formation process, and material behavior at the element scale exhibits brittle fracture or ductile, irrecoverable deformation that may be captured by hardening/softening plasticity models with nonassociated flow. Sea ice is highly cross-anisotropic and it behaves as a frictional material. Interaction between floes in the ice pack resembles that observed in granular materials. These materials are frictional in nature, they exhibit both contractive and dilative volume changes, the plastic flow is nonassociated, and their stiffnesses and strengths increase with confining pressure. Formation of leads and subsequent freezing of the water results in cementation between the ice floes, and the ice pack becomes stronger. It may be compared with the behavior of cemented soils. For these materials increasing amounts of cementation results in increasing rates of dilation when sheared, and this accounts for the largest contribution to the increase in shear strength. Constitutive modeling of these behavior characteristics may be achieved by models used for frictional materials.