Collaborative Research: Simulating Iceberg Calving from Ice Shelves using a Damage Mechanics Model

合作研究：使用损伤力学模型模拟冰架崩解的冰山

• 批准号: 1341428
• 负责人: Ravindra Duddu
• 金额: $ 20万
• 依托单位: Vanderbilt University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1341428&HistoricalAwards=false
• 关键词: Collaborative; Research; Simulating; Iceberg; Calving

Bassis/1341568This award supports the development of a model that can simulate both the flow and fracture of glacier ice, (including the slow creeping of that ice) as it spreads under its own weight all the way to the complete failure and detachment (calving) of icebergs from glaciers and ice shelves (floating expanses of glacier ice). Because iceberg calving accounts for nearly 50% of the mass lost from ice shelves, it plays an important role in the mass balance of glaciers and ice sheets, but remains a poorly understood process. Iceberg calving is also not yet accounted for in the current generation of continental-scale ice sheet models, which are used in state-of-the-art climate simulations and sea level rise projections, because simulating iceberg calving requires that we understand the initiation and propagation of fractures within the ice over timescales that can range from a few seconds to decades or even centuries. To address this problem, the primary objective of this project is to address this gap in our understanding by translating physical and computational approaches originally developed to simulate the fracture of quasi-brittle materials, like metals and concrete, to the fracture of glacier ice. Since it is both impossible and impractical to simulate the propagation of each individual crack in an ice sheet, we will seek a "continuum damage mechanics" approach that handles collections of cracks in a physically and thermodynamically consistent way to simulate failure at the large scale. This will be accomplished by using an approach that can simulate what happens to fractures after they form at the interface with the ocean. This project seeks to advance our ability to predict the fate of the Greenland and Antarctic ice sheets and to quantify the ice sheet contribution to sea level rise in the coming centuries. Accomplishing this requires that we have a better understanding of why icebergs that can exceed the size of small New England States, detach and drift away from ice shelves. The broader impacts of the project also include graduate and undergraduate education through directed research projects and targeted engagement of under-represented minorities in low-income regions at the elementary and high school levels. Engagement with under-represented minorities will include counseling and planning for future career paths in the STEM fields and mentoring selected students during summer internship programs hosted by the University of Michigan, Vanderbilt University and Columbia University.

Bassis/1341568此奖项支持可以模拟冰川冰的流量和断裂（包括冰的缓慢蠕动）的模型的开发，因为它一直以其自身的体重扩散，直至完全失败和脱离冰川和冰淇淋的完全故障和脱离（产犊）。 由于冰山产犊占冰架中质量损失的近50％，因此它在冰川和冰盖的质量平衡中起着重要作用，但仍然是一个鲜为人知的过程。 在当前一代的大陆尺度冰盖模型中，冰山产犊也尚未考虑，这些模型用于最先进的气候模拟和海平面上升的预测，因为模拟冰山产犊模拟，我们需要我们了解我们了解冰层中冰的起始和传播在冰上的裂缝范围内的时间表，这可能范围从几秒钟到几秒钟到几十秒甚至百分比。 为了解决这个问题，该项目的主要目的是通过翻译最初开发的物理和计算方法来解决我们的理解差距，该方法最初开发出来，以模拟准脆性材料（例如金属和混凝土）的断裂，以将其裂解为冰川冰的裂缝。 由于模拟冰盖中每个单独裂缝的传播既是不可能又不切实际，因此我们将寻求一种“连续损害力学”方法，该方法可以在物理和热力学上处理裂纹的收集，以大规模模拟失败。这将通过使用一种方法来模拟裂缝在与海洋界面形成后发生的事情来实现。该项目旨在提高我们预测格陵兰和南极冰盖命运的能力，并量化未来几个世纪以来对海平面上升的冰盖贡献。 实现这一目标要求我们更好地了解为什么要超过新英格兰小州大小的冰山，从冰架上脱离并漂移。 该项目的更广泛影响还包括通过指导研究项目的研究生和本科教育，并针对小学和高中级别低收入地区代表性不足的少数民族的参与。 与代表性不足的少数民族的交往将包括在STEM领域的未来职业道路和计划中的咨询和计划，并在密歇根大学，范德比尔特大学和哥伦比亚大学主持的暑期实习计划中指导选定的学生。

项目成果

On the evaluation of the stress intensity factor in calving models using linear elastic fracture mechanics

• DOI: 10.1017/jog.2018.64
• 发表时间: 2018-09
• 期刊: Journal of Glaciology
• 影响因子: 3.4
• 作者: S. Jiménez;R. Duddu

Modeling hydraulic fracture of glaciers using continuum damage mechanics

• DOI: 10.1017/jog.2016.68
• 发表时间: 2016-08
• 期刊: Journal of Glaciology
• 影响因子: 3.4
• 作者: M. Mobasher;R. Duddu;J. Bassis;H. Waisman

An updated-Lagrangian damage mechanics formulation for modeling the creeping flow and fracture of ice sheets

用于模拟冰盖蠕动流和破裂的更新拉格朗日损伤力学公式

• DOI: 10.1016/j.cma.2016.09.034
• 发表时间: 2017
• 期刊: Computer Methods in Applied Mechanics and Engineering
• 影响因子: 7.2
• 作者: Jiménez, Stephen;Duddu, Ravindra;Bassis, Jeremy
• 通讯作者: Bassis, Jeremy