Mechanics of Iceberg and Sea Ice Failure in Offshore Engineering Applications

加拿大拥有丰富的自然资源，包括北极和亚北极地区巨大的潜在矿产和碳氢化合物储量。加拿大的北方战略也是国家政策的重要组成部分，其中促进经济发展、保护环境和维护主权是重要目标。主权的主张将需要一支能够在北极全年作业的破冰船船队。本文提出的研究将促进对极端冰载荷和相关破坏过程的更好理解，并与未来此类船舶的建造高度相关。此外，加拿大北部的开发意味着航运活动、石油和天然气勘探以及北部基础设施项目的增加。海冰和冰川冰的存在是为此类开发进行安全、经济的船舶和结构设计的主要考虑因素。对于拉布拉多海和加拿大北极东部(例如巴芬湾)等非常有希望开发近海石油和矿产的地区来说，海冰覆盖中嵌入的巨型冰特征(例如多年的海脊、冰山和冰岛碎片)的存在给设计师带来了重大的新挑战。虽然现有的方法和最佳做法既可用于在海冰中作业，也可用于在开阔水域有冰山的区域作业，但需要新的办法来改进与海冰中嵌入的块状冰特征相互作用的模型。 从设计的角度来看，与冰破碎失效相关的极端冰荷载是一个基本的考虑因素。冰的压缩破坏是一个复杂的过程，在冰-结构相互作用过程中，接触在高压区的局部化是一个重要方面。在动态冰碎失败过程中避免不必要的结构振动也是非常重要的。破裂过程以及由于微结构改变导致的压力软化在压缩冰破坏中起着重要作用。还需要对与大量冰块特征的破坏和破裂相关的大规模裂缝进行建模，并且与这些裂缝相关的随机性要求采用概率方法。在这一领域，许多问题仍然没有得到回答。该计划的总体目标是减少冰破裂过程知识中的不确定性，并改进用于与冻结在海冰中的嵌入块状冰特征相互作用的结构设计方法。将通过创新的实验和理论模拟程序来探索不同类型冰之间的冰破坏和界面粘结特性。重点是了解相互作用力学和冰川破裂过程的基本方面。培训HQP以培养下一代加拿大北极专家是该计划的另一个非常重要的目标。

Canada has a wealth of natural resources, including vast potential mineral and hydrocarbon reserves in arctic and subarctic regions. Canada’s Northern Strategy also serves as a vital part of national policy in which promoting economic development, protecting the environment and assertion of sovereignty are important objectives. The assertion of sovereignty will necessitate a fleet of ice-breaking vessels capable of year-round operations in the Arctic. The research proposed herein will promote greater understanding of extreme ice loads and associated failure processes and is highly relevant to future construction of such vessels. Moreover, the development of Canada's north implies increased shipping activity, oil and gas exploration, as well as northern infrastructure projects. The presence of sea ice and glacial ice is a dominant consideration in the safe, economic design of ships and structures for such developments. For regions such as the Labrador Sea and eastern Canadian Arctic (e.g. Baffin Bay), which are highly prospective for offshore oil and mineral developments, the presence of embedded massive ice features (e.g. multi-year ridges, icebergs and ice island fragments) frozen into the sea ice cover presents designers with significant new challenges. While established methods and best practices are available for either operations in sea ice or for operations in regions with icebergs in open water, new approaches are needed to improve the modelling of interactions with embedded massive ice features in sea ice. From a design perspective, extreme ice loads associated with ice crushing failure is an essential consideration. Compressive failure of ice is a complex process, and the localization of contact into high pressure zones (hpzs) during an ice-structure interaction is an important aspect. Avoiding unwanted structural vibrations during dynamic ice crushing failure is also highly relevant. Fracture processes, as well as pressure softening due to microstructural modification, play an important role in compressive ice failure. Large-scale fractures associated with the failure and break-out of massive ice features also need to be modeled and randomness associated with these fractures necessitates a probabilistic approach. Many questions remain unanswered in this area. The overall goal of the program is to reduce uncertainty in the knowledge of ice failure processes and improve methods used in the design of structures for interactions with embedded massive ice features frozen in sea ice. Ice failure and interface bond properties between dissimilar ice types will be explored through an innovative experimental and theoretical modeling program. Focus is placed on understanding fundamental aspects of interaction mechanics and ice fracture processes.The training of HQP to build the next generation of Canadian Arctic experts is another highly important goal of this program.