An assessment of sensitivity of the self-excited modelling approach for simulating dynamic ice-structure interactions to changes in temperature and scale effects

Abstract

Empirical relationships of compressive ice strength as a function of stress rate have been utilized in models of vibrations that arise during coupled ice-structure interactions. Central to current self-excited models (SEM) is a deterministic relationship of compressive ice strength as a function of stress rate based on uniaxial compressive strength data obtained from thin, first-year sea ice. However, full-scale observations, laboratory test data and fundamental knowledge of ice material behavior suggest that any such relationship would be influenced by factors such as temperature and the scale of the interaction. In this paper, the influence of temperature and scale effects is examined and first-order estimates of their effect on modifying the assumed strength vs. stress rate relationship are presented. This approach is used to assess the sensitivity of the SEM method to changes in environmental and interaction conditions. Results suggest that accounting for changes in ice temperature and the scale of interaction considerably affect ice-induced vibration responses predicted by the model. Additional large-scale experiments, full-scale data and the development of physics-based models of ice compressive failure are needed to better account for different ice conditions and different sized structures that may be considered in design.