Influence of Scale on the Constitutive Behavior of Sea Ice

Abstract

The development of physically based constitutive models for sea ice has proven difficult because of a lack of knowledge about the underlying deformation mechanisms, and the lack of unambiguous experimental data at meaningful sizes. However, these shortcomings have been addressed to a measurable extent by the development of effective cyclic loading techniques for laboratory and in-situ experiments, coupled with an improved knowledge of the underlying deformation mechanisms. This progress has made it possible to develop a physically based constitutive model and verify it at meaningful scales. The paper examines the cyclic loading response of in-situ specimens of first-year sea ice ranging in size from 4 × 4 m² to 30 x 30 m² in the horizontal plane, along with results from laboratory experiments on field cores. The model predictions compare favorably with the field observations, and an essentially scale-independent constitutive response emerges. The in-situ experiments provide insight regarding the relaxation time distribution, and the anelastic and viscous components of strain. The results from acoustic emission monitoring during the in-situ experiments are also presented.