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https://hdl.handle.net/11681/9071| Title: | Profile properties of undeformed first-year sea ice |
| Authors: | United States. Naval Sea Systems Command David W. Taylor Naval Ship Research and Development Center Cox, G. F. N. (Gordon F. N.) Weeks, W. F. |
| Keywords: | Ice Ice mechanics Ice properties Sea Ice Central Arctic Basin EPOLAR |
| Publisher: | Cold Regions Research and Engineering Laboratory (U.S.) Engineer Research and Development Center (U.S.) |
| Series/Report no.: | CRREL report ; 88-13. |
| Description: | CRREL Report Abstract: In many sea ice engineering problems the ice sheet has been assumed to be a homogeneous plate whose mechanical properties are estimated from the bulk salinity and average temperature of the ice sheet. Typically no regard has been given to the vertical variation of ice properties in the ice sheet or to the time of ice formation. This paper first reviews some of the mechanical properties of sea ice, including the ice tensile, flexural and shear strengths, as well as the ice modulus. Equations for these properties are given as functions of the ice brine volume, which can be determined from the ice salinity and temperature. Next a numerical, finite difference model is developed to predict the salinity and temperature profiles of a growing ice sheet. In this model ice temperatures are calculated by performing an energy balance of the heat fluxes at the ice surface. The conductive heat flux obtained from the energy balance is then used to calculate the rate of ice growth and ice thickness by applying the Stefan ice growth equation. Ice salinities are determined by considering the amount of initial salt entrapment at the ice/water interface and the subsequent brine drainage due to brine expulsion and gravity drainage. Ice salinity and temperature profiles are then generated using climatological data for the Central Arctic Basin. The profiles appear to be realistic and agree reasonably well with field data. Finally the predicted salinity and temperature profiles are combined with the mechanical property data to provide mechanical property profiles for first-year sea ice of different thicknesses, grown at different times of the winter. The predicted profiles give composite plate properties that are significantly different from bulk properties obtained by assuming homogeneous plates. In addition the failure strength profiles give maximum strengths in the interior of the sheet as contrasted with the usual assumption of maximum strength at the cold, upper ice surface. Surprisingly the mechanical property profiles are only a function of the ice thickness, independent of the time of ice formation. |
| Rights: | Approved for public release; distribution is unlimited. |
| URI: | http://hdl.handle.net/11681/9071 |
| Appears in Collections: | CRREL Report |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| CRREL-88-13.pdf | 1.05 MB | Adobe PDF |  View/Open |