A nonlinear constitutive model for ice

Abstract A six-parameter nonlinear model consisting of two springs and two dashpots is developed to represent the primary and secondary/steady creep stage of ice, the parameters of which are adjusted so as to obtain a creep function in agreement with experimental data and with standard creep rate expressions as given, for example, by Voitkovski[1]. The constitutive law for the model is derived in differential form and is applied to the time-deflection behaviour of imperfect simply-supported ice columns subjected to a constant axial load. The method of solution and step-by-step numerical integration technique introduced allows the use of the constitutive law in its ‘exact’ form. Results presented for a range of stress levels and temperatures indicate that such structures are inherently unstable and that the time to failure is very sensitive to these parameters.