[PDF] Theory Of Floating Ice Sheets eBook

Author : D. E. Nevel
Publisher :
Page : 122 pages
File Size : 35,67 MB
Release : 1976
Category : Ice
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The problem investigated in this thesis is the prediction of the deflection and stresses in a floating ice sheet under loads which act over a long period of time. This problem is currently important for oil exploration offshore in the Arctic. A review of analytical methods for predicting the bearing capacity of an ice sheet is given. The problem is formulated by assuming the ice is isotropic with a constant Poisson's ratio. The shear modulus is assumed to obey a linear viscoelastic model. The specific model selected is a series of one Maxwell model and two Voigt models. One of the Voigt models has a negative spring constant which produces tertiary creep. The ice model exhibits a primary, secondary, and tertiary creep response, similar to that observed in uniaxial creep tests of ice. The material properties in the viscoelastic model may be a function of the vertical position in the ice sheet, but all these material properties must be proportional to the same function of position. Using the thin-plate theory for the floating ice sheet, the solution is obtained for the deflection and stresses in the ice sheet for primary, secondary, and tertiary creep regions. It is then shown that for a load that is not distributed over a large area, the time-dependent part of the deflection and stresses is relatively independent of the load's distribution. For the elastic case, the stress significantly depends upon the load's distribution. Results are given for the deflection and stresses as a function of time and distance from the load. The maximum deflection and stresses occur at the center of the load. At this point the deflection increases with time, while the stresses decrease; i.e., the stresses relax. (Author).

Author : D. E. Nevel
Publisher :
Page : 6 pages
File Size : 32,66 MB
Release : 1966
Category : Ice
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In the previous year this author, D.E. Nevel, and G. Frankenstein both wrote papers on ice sheets. In this paper Nevel compares the results of freshwater ice and sea ice that Frankenstein published to his own theory on time dependent deflection under a uniformly distributed load on a floating ice sheet.

Author : Arnold D. Kerr
Publisher :
Page : 52 pages
File Size : 21,96 MB
Release : 1975
Category : Ice
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This report contains a critical survey of the literature on the bearing capacity of floating ice plates. It consists of a discussion of general questions, a critical survey of analytical attempts to determine the bearing capacity of floating ice plates, and a survey of field and laboratory tests on floating ice plates and their relation to the analytical results. The paper concludes with a systematic summary of the results, a discussion of observed shortcomings, and suggestions for needed investigations.

Author : D. H. Garbaccio
Publisher :
Page : 100 pages
File Size : 11,43 MB
Release : 1968
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Using a digital computer calculations were made of the deformations and bending moments in a floating ice sheet. The ice behavior was described by a linear viscoelastic model consisting of a Maxwell and a Voigt element in series. Loading with circular symmetry uniformly distributed was applied to a plate of finite thickness described by Reissner theory. The effect of superposed loads describing aircraft landing gear was considered. Calculations were also made for a linearized approximation to the problem of a thin sheet described by a power creep law. The method was only partially successful because the time span of applicability was short. (Author).

Author : NATIONAL ENGINEERING SCIENCE CO PASADENA CA.
Publisher :
Page : 34 pages
File Size : 28,28 MB
Release : 1965
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Report of experimental results on the interaction behavior of floating ice sheets with infinitely deep water gravity waves using model similitude theory. The results indicate a considerable dampening effect on the water wave by the ice sheet. A comparison of experiment results with a mathematical model developed for ice floe behavior indicate a fairly good qualitative agreement but the reaction of the experiment model was below that predicted by the mathematical model. (Author).