Constitutive modeling of the visco-plastic behavior of ice

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:398056

Azizi, F ^[1]; Whalley, W B ^[2]

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1. Univ. of Plymouth (United Kingdom)
2. Queen`s Univ., Belfast, Northern Ireland (United Kingdom)

Over the years, a great variety of semi-empirical and theoretical models for ice and frozen soils have been established. More recently, fundamentally different types of stress-strain-time constitutive relationships based upon thermo-mechanics and visco-plastic flow theories, coupled with numerical analysis, have been pursued. These models, however simple (or complex) contain empirical parameters measured from laboratory or from in-situ experiments and the paper highlights some of the methods used to determine parameters such as the exponents of the power law in the case of ice. Of particular interest, it was found that for polycrystalline ice, the time exponent for Hult`s primary creep law has a constant value of around 2/3 regardless of the magnitude of stresses or the temperature variation. On the other hand, the paper shows that the secondary creep behavior of such a material can be predicted using results measured from the primary creep phase. This is of significance since for polycrystalline ice, secondary creep, when it occurs, is usually reduced to an inflection point on the strain-time curve heralding the beginning of tertiary creep and hence failure. The paper also discusses the validity of Fish`s viscoplastic flow model in conjunction with results measured from different types of laboratory tests (uniaxial and pressuremeter tests) carried out on polycrystalline ice.

• OSTI ID: 398056
• Report Number(s): CONF-940409--; ISBN 1-880653-10-9
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
BENCH-SCALE EXPERIMENTS
CREEP
DEFORMATION
FAILURES
ICE
MATHEMATICAL MODELS
OFFSHORE PLATFORMS
POLAR REGIONS
SHIPS
STRAINS
STRESS INTENSITY FACTORS