Contribution of Primary Creep in Modeling the Mechanical Behavior of Polycrystalline Ice

In most of the models proposed for deformation of ice, in addition to instantaneous elastic and viscoelastic parts, a viscoplastic part is also considered. An expression used for material secondary creep is usually employed to describe the viscoplastic component. In this study, however, another viscoplastic deformation of primary creep type is also considered in addition to the secondary creep. Therefore the permanent contribution of deformation is suggested to consist of primary and secondary creep parts. The existence of the primary creep contribution is investigated and characterized by using experimental results reported in the literature. The identified primary creep contribution is then validated by other available experimental results. Finally, the significance of primary creep in the inelastic behavior will be discussed.