On the evaluation of the stress intensity factor in calving models using linear elastic fracture mechanics
On the evaluation of the stress intensity factor in calving models using linear elastic fracture mechanics
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DOI：
10.1017/jog.2018.64
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发表时间：
2018-09
影响因子：
3.4
通讯作者：
S. Jiménez;R. Duddu
中科院分区：
文献类型：
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作者：
S. Jiménez;R. Duddu
摘要我们使用线弹性断裂力学（LEFM）从文献中研究产犊或决口模型的适当性。为此，我们比较LEFM模型预测的应力强度因子（SIF）对数值计算的SIF使用位移相关法结合有限元法。我们提出了几个基准模拟，其中我们计算的SIF在不同的边界条件下，包括接地和浮动条件下，通过矩形冰板的水填充表面和基裂隙的尖端。模拟结果表明，底部边界条件对裂隙尖端应力强度因子有显著影响。我们发现，现有的产犊模型使用LEFM一般不准确的评估SIF在地面冰川或浮动冰架。我们还说明，使用“单边裂纹”的LEFM配方的权重函数可能是适当的预测产犊从浮冰架，由于冰的断裂韧性低，而使用“双边裂纹”或“中央通过裂纹”的权重函数是更适合预测产犊从接地冰川。总之，我们建议使用位移相关法的应力强度因子评估在真实的冰川和冰架复杂的几何形状和边界条件。
ABSTRACT We investigate the appropriateness of calving or crevasse models from the literature using linear elastic fracture mechanics (LEFM). To this end, we compare LEFM model-predicted stress intensity factors (SIFs) against numerically computed SIFs using the displacement correlation method in conjunction with the finite element method. We present several benchmark simulations wherein we calculate the SIF at the tips of water-filled surface and basal crevasses penetrating through rectangular ice slabs under different boundary conditions, including grounded and floating conditions. Our simulation results indicate that the basal boundary condition significantly influences the SIF at the crevasse tips. We find that the existing calving models using LEFM are not generally accurate for evaluating SIFs in grounded glaciers or floating ice shelves. We also illustrate that using the ‘single edge crack’ weight function in the LEFM formulations may be appropriate for predicting calving from floating ice shelves, owing to the low fracture toughness of ice; whereas, using the ‘double edge crack’ or ‘central through crack’ weight functions is more appropriate for predicting calving from grounded glaciers. To conclude, we recommend using the displacement correlation method for SIF evaluation in real glaciers and ice shelves with complex geometries and boundary conditions.