A constitutive creep model for single crystal ice has been formulated
based on the experimental results and the mechanism of the multiplicat
ion process of mobile dislocations. In this model, the primary mechani
sm is considered to be the dislocation motion on the basal planes of s
ingle crystal ice due to strong creep anisotropy. The preferred crysta
llographic orientation and temperature of single crystal ice are incor
porated in describing both the elastic and the inelastic deformations
in the creep model. Material properties used in the model are the disl
ocation velocity and the changing dislocation density of single crysta
l ice based on experimental data. The proposed uniaxial creep model is
extended to a biaxial model by allowing inelastic deformation only al
ong the basal planes. Parametric studies are performed to better under
stand the dependence of macroscopic stress-strain curves on microstruc
tural parameters. The results show strong influence of the loading rat
e and stress level. Comparison of the model predictions with experimen
tal data shows excellent agreement over a range of strain rates.