A viscoelastic integral formulation and numerical implementation of an isotropic constitutive model of saline ice

This work develops a multiaxial numerical implementation of a constitutive model of saline ice which is based on dislocation processes and grain boundary relaxation. The model includes contributions from the elastic, anelastic (time-dependent recoverable), and viscous (time-dependent non-recoverable) straining mechanisms. The anelastic strain model is formulated using a creep compliance tensor and a hereditary integral formulation. The incremental form of the constitutive model is derived and its implementation into finite element software is discussed. We compare our model to multiple experimental data sets including cyclic sinusoidal and creep loading. We find that our model compares well with the experimental data and is able to capture the mechanical behavior of ice across multiple temperatures, loading frequencies, stresses, and timescales.