An anisotropic viscous-plastic constitutive law (AVP) is proposed. It is formulated along the lines developed by Coon, et al. (1998) for an anisotropic elastic-plastic law (AEP). The geophysical-scale ice is assumed to be oriented (Pritchard, 1998), with ice strengths defined by the thickness distribution of ice having each orientation. The yield surface is assumed to be the smallest surface containing the yield surfaces of ice having each orientation. A normal flow rule is assumed. Stresses within the yield surface are assumed to be on a pseudo-yield surface that is similar to the actual yield surface, with the pseudo-strength scaled by the magnitude of the stretching tensor. Stretching here also satisfies a flow rule associated with the pseudo-yield surface.
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