Umfang:
V, 93 S. : Ill., graph. Darst.
ISBN:
0644005602
Serie:
ANARE Reports 132
Inhalt:
One of the weakest links in present ice dynamics models is the lack of an adequate empirical flow law for polycrystalline ice in its natural state. Inadequacies include a paucity of creep data relevant to cold ice masses and a general neglect of the effects of preferred crystal orientation fabrics. The present study reports the results of 150 000 hours of creep tests on isotropic aggregates replicating conditions of temperature and shear stress relevant to polar ice masses, from which an extended isotropic flow law has been constructed. It is shown how anisotropic crystal orientation fabrics can be incorporated into such a flow law. The quantitative model developed for this purpose is made possible by: (a) the definition of a normalised third deviatoric stress invariant as a configuration parameter describing the geometrical distribution of shear stress; and (b) a reinterpretation of the scalar geometric factor employed in the analysis of monocrystalline creep as a tensor coefficient of correlation between the orientation fabric and the stress configuration parameter. Laboratory experiments are presented to substantiate the validity of the model.
Anmerkung:
MAB0014.001: ZSP-123-132
,
Alte Signaturen: AQ 2501/132 ; 85.330 ; Th 20.692
In:
ANARE Reports
