Anisotropic Sea Ice Indentation in the Creeping Mode
Introduction The interaction of an ice sheet with a vertically faced indcnter is an important loading condition for cylindrical structures and conical structures with grounded rubble pile or accreted ice foot in the Arctic. In general, this indentation phenomenon is characterized by the simultaneous...
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Language: | English |
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Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1076.9154 http://offshoremechanics.asmedigitalcollection.asme.org/data/Journals/JMOEEX/28041/211_1.pdf |
Summary: | Introduction The interaction of an ice sheet with a vertically faced indcnter is an important loading condition for cylindrical structures and conical structures with grounded rubble pile or accreted ice foot in the Arctic. In general, this indentation phenomenon is characterized by the simultaneous occurrence of viscous (rate-dependent) and fracture behavior. Several theoretical models based on approximate methods of analysis that idealize the ice sheet as an isotropic continuum have been proposed for predicting global ice forces. Ting and Shyam Sunder [6] have applied the (approximate) strain path method of analysis to study interface pressures during plane strain indentation. Their study showed that approximate methods of analysis cannot adequately model interface adfreeze and friction, factors that can significantly influence ice load predictions. In a recent paper Sea ice, however, is not an isotropic material. Field observations have shown that this type of ice, which is predominantly columnar, has two sources of anisotropy: (a) the c-axis is oriented perpendicular to the axis of crystal growth, and (b) the c-axes of different crystals may show preferred azimuthal orientation in the plane on which they lie. There is strong evidence suggesting that the preferred azimuthal orientation is correlated with the instantaneous current direction just underneath a growing ice sheet |
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