Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Archives of Mechanics

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: polycrystalline ice

Sortuj według:

Ogranicz wyniki do:

A uniform strain, discrete-grain model for evolving anisotropy of polycrystalline ice

Staroszczyk R.

Archives of Mechanics

2002

Vol. 54, nr 2

103-126

A discrete-grain model accounting for the induced anisotropy of polycrystalline ice is formulated. An individual ice crystal is supposed to be a transversely isotropic medium whose behaviour is linearly viscous. For such a crystal a frame-indifferent constitutive law involving three microscopic rheological parameters is derived. Assuming that each crystal undergoes a homogeneous deformation of the polycrystalline aggregate (the Taylor approximation), the macroscopic viscous behaviour of the material is determined. The considerations are illustrated by the results of numerical simulations of simple flows, showing the evolution of the oriented structure of the material and the variation of macroscopic viscosities with increasing strains. In addition, the influence of the parameters describing the single crystal anisotropy on the overall behaviour of the aggregate is investigated.

An inhomogeneous variational model applied to predict the behaviour of isotropic polycrystalline ice

Gagliardini O., Arminjon M., Imbault D.

Archives of Mechanics

2001

Vol. 53, nr 1

3-21

A model for the prediction of the viscoplastic behaviour of polycrystalline ice is presented. This model is based on the minimization of the dissipation energy under the principle of minimal heterogeneity. The grain is supposed to behave as a linear transversely isotropic medium depending on one anisotropy parameter. Anisotropic textures can be considered, but the present numerical results are for an isotropic texture. The model then predicts a linear isotropic behaviour involving an effective viscosity. The latter depends on the prescribed value for the strain-rate heterogeneity and on the grain anisotropy parameter. The present model is compared with a self consistent model built under the same assumptions for the grain behaviour. The deviation from the no-correlation condition is studied.