An analytical approach to deformation of anisotropic ice-crystal aggregates / Throstur Thorsteinsson.

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100 1# ‡aThorsteinsson, Throstur.
245 13 ‡aAn analytical approach to deformation of anisotropic ice-crystal aggregates /‡cThrostur Thorsteinsson.
260 ## ‡a[S.l.] :‡b[s.n.],‡c2001.
300 ## ‡ap. 507-516 :‡bdiags.
500 ## ‡aJournal of Glaciology. Vol. 47(158) :507-516 (2001).
500 ## ‡aSymbols for Cauchy stress tensor and strain-rate tensor are missing throughout equations (1) to (12)
520 3# ‡aInvestigates non-linear deformation of anisotropic polycrystalline ice in various combinations of stress states and with prescribed fabrics similar to those found in ice sheets. Uses homogeneous stress assumption to formulate analytical anisotropic flow law. Non- linearity of flow law leads to non-linear coupling of deviatoric stress components in the bulk. Formulation general enough to apply to anisotropic materials other than ice. Examines deformation rate of single crystals deforming by glide in basal plane. Bulk deformation rate then average of individual crystal rates (volume fractions for non-uniform grain size). Assumes fabrics are girdle fabrics with vertical axis of rotational symmetry. Presents modelled velocity gradient components and normalised strain rates (enhancement factors) as function of cone angle for simple stress states. Maximum enhancement in simple shear is 4.375, while lab experiments often indicate a value close to 9. Compares results with three-parameter model due to Johnson, which author concludes misses details but offers an efficient way to account for major effects for highly complicated stress states. Examines laminar flow with a simple vertical fabric profile, finding surface velocity 2.36 times larger for anisotropic than for isotropic ice.
650 07 ‡a551.322 -- Ice and snow.‡2udc
650 07 ‡a53 -- Physics.‡2udc
650 07 ‡a548.2 -- Ice, granular structure. Anisotropy.‡2udc
650 07 ‡a539.37 -- Ice, plastic and viscous deformation.‡2udc
650 07 ‡a519.673 -- Modelling.‡2udc
650 07 ‡aE4 -- Glaciology: physics and chemistry of ice.‡2local
773 0# ‡7nnas ‡tJournal of Glaciology. ‡gVol. 47(158) (2001) ‡wSPRI-20534
917 ## ‡aUnenhanced record from Muscat, imported 2019
948 3# ‡a20240416