Development of a viscoelastic phase field model for fracture processes with application to ice dynamics

点击翻译按钮获取中文摘要

The propagation of cracks in floating ice tongues results in the break-off of large icebergs. This process is referred to as calving. The understanding of calving is of great importance for the judgement of the consequences of climate warming. An increased calving leads to an accelerated flow of meteoric ice into the oceans, which is followed by a sea level rise. To model complex crack propagation phenomena in floating ice tongues a viscoelastic constitutive law of ice based on a non-linear Maxwell model is combined with a fracture mechanical phase field. The modeling is pursued in successive steps, resulting in geometrically and constitutively non-linear Lagrangian description of the material flow in conjunction with a fracture phase field. The model is implemented in the finite element toolbox FEniCS and allows for the simulation of complex crack patterns in floating ice tongues. The creation, propagation, arrest, and branching of cracks can be considered. As an application scenario the Nioghalfjerdsbrae glacier in Greenland is investigated.