HR: 15:10h
AN: C12B-06    [PDF]
TI: A Description Of Crevasse Formation Using Continuum Damage Mechanics
AU: * Pralong, A
EM: pralong@vaw.baug.ethz.ch
AF: Section of Glaciology, VAW, ETH-Zurich Gloriastr. 37, Zurich, 8092 Switzerland
AU: Funk, M
EM: funk@vaw.baug.ethz.ch
AF: Section of Glaciology, VAW, ETH-Zurich Gloriastr. 37, Zurich, 8092 Switzerland
AU: Luethi, M P
EM: luthi@gi.alaska.edu
AF: Geophysical Institute, University of Alaska 903 Koyukuk Drive, Fairbanks, AK 99775 United States
AB: Continuum damage mechanics describes the progressive deterioration of material subjected to loading. For polycrystalline ice, a local isotropic damage evolution law coupled to Glen's flow law allows the description of creep to failure. The damage evolution law has been derived from mesoscopic tests performed in traction and shearing. Damage initiation is controlled by a size dependent stress threshold, which has been inferred from published data of laboratory experiments. Crack healing is considered by a simple dynamic law. The rheology of the damaged ice is implemented in a FE model to describe the formation of crevasses at a macroscopic scale. A level set method is applied to model the evolution of the glacier geometry. The main purpose of this investigation is the modelling of the destabilization of large ice masses from hanging glaciers. The rupture of large ice chunks has been computed for different hanging glaciers in Switzerland. Numerical results compared with field observations and measurements showed good agreement. The ability of the model to describe phenomena connected to crevasse opening seems to be promising for other glaciological applications such as rift opening or ice stream margin formation.
DE: 1827 Glaciology (1863)
DE: 1863 Snow and ice (1827)
DE: 3220 Nonlinear dynamics
DE: 5104 Fracture and flow
SC: Cryosphere [C]
MN: 2003 Fall Meeting