One-Dimensional Viscoelastic Simulation of Ice Behaviour in relation to Dynamic Ice Action

Abstract

When level ice is approaching the structure it exhibits the cyclic stress with in an increasing amplitude. The uniaxial compression cyclic tests of ice, performed at University Centre on Svalbard in 2007 (Sæbø, 2007), indicated an increase in the ice sample stiffness. The objective of this study was to verify whether this phenomenon can be explained by viscoelastic behaviour of ice.Linear viscoelastic Kelvin, Maxwell and Burgers models were implemented into Matlab by means of the Boltzmann principle of superposition in order to simulate the behaviour of ice under cyclic loading. The Burgers model was calibrated with the creep test, performed by Sinha (Sinha, 1978), in order to get the input parameters specific for simulation of ice behaviour.An extensive sensetivity analysis of the model were carried out and confirmed that the increase of the modulus of elasticity of ice under cylic loading can be explained by concept of viscoelasticity. However, the degree of this increase is different from the one obtained in uniaxial compression cyclic test. A precise behaviour of ice in this experiment cannot be described by means of the linear viscoelastic model of ice.