Numerical MPM Solution of Sea Ice Dynamics with an Elastic-Decohesive Constitutive Model

A numerical technique called the material-point method (MPM) shows promise for treating problems of ice dynamics. MPM is based on particle-in-cell technology and thus uses a Lagrangian set of material points with associated mass, position, velocity, stress, and other material parameters, and a background mesh where the momentum equation is solved. This method avoids the convection errors associated with fully Eulerian methods as well as the mesh entanglement that can occur with fully Lagrangian methods under large deformations. Example calculations are performed for a rectangular region of Arctic ice using a newly-developed elastic-decohesive constitutive model. In the simulations, the ice motion is wind-driven and resisted by ocean drag. Two adjacent sides of the rectangle are rigid shorelines and the other two edges are free surfaces that can deform freely. These MPM calculations are compared with published finite element simulations using a viscous-plastic rheology.