Large-scale simulation of pneumatic and hydraulicfracture with a phase-field approach

采用相场方法对气动和水力压裂进行大规模模拟

• 批准号: 255801726
• 负责人: Professor Dr.-Ing. Christian Hesch
• 金额: --
• 依托单位: Department Maschinenbau
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/255801726?language=en
• 关键词: Large; scale; simulation; pneumatic; hydraulicfracture

One of the main challenges in computational fracture mechanics is to predict and track crack paths and fragmentation patterns. In fact, besides the high demands on the modeling side, the complicated structure and non-regular behavior of cracks requires highly sophisticated mesh refinement and discretization techniques. Both aspects turn the numerical simulation of crack problems into a difficult task, thereby providing a major obstacle for the development of efficient and reliable simulation tools in fracture mechanics. It is the goal of this project to address this challenge by developing a new theoretical and methodological framework for fracture mechanics, which will in particular allow for the numerical simulation of large-scale problems on recent and upcoming parallel architectures. In order to achieve this goal, on the modeling side, the framework will exploit phase-field models as a novel approaches for the representation of crack interfaces. On the side of the discretisation methods, we will be able to make use new technologies as NURBS based ansatz spaces. One important aspect of these discretisation methods is their superior stability properties when compared to traditional Lagrangian approaches. In particular in the context of large deformations, this is a considerable advantage. This stability, however, comes at a price, as NURBS require the consistent handling of larger patches which poses challenges when it comes to the development of efficient adaptive techniques. Here, with patchwise or lightweight adaptivity, we will employ recent developments combining the flexibility of traditional refinement techniques with a patchwise view on the discretisation, thereby allowing for the design of efficient approaches on massively parallel architectures. In addition to the new phase-field based approach for fracture we will also extend our new framework in order to deal with contact and frictional effects along the larger interior crack interfaces. In this way, our new framework will be capable of dealing with both, strongly non-linear as well as non-smooth effects, in a consistent manner.This project will build on complimentary expertise in engineering, modeling, computational science, and high performance computing in order to establish a common basis for the development of non-conventional finite element methods for large-scale simulations of variationally and thermodynamically consistent multi-physics phase-field fracture models undergoing finite deformations. The new framework emerging from this project will provide a number of new and non-standard computational tools, which will be developed and tested along the simulation of pneumatic and hydraulic fracturing. However, the resulting framework will be designed in a flexible way which will allow its application also beyond hydraulic fracturing, thereby on the long run possibly serving as the basis for a new class of modeling and simulation tools.

计算断裂力学的主要挑战之一是预测和跟踪裂纹路径和断裂模式。事实上，除了建模方面的高要求外，裂纹的复杂结构和不规则行为需要高度复杂的网格加密和离散化技术。这两个方面都使裂纹问题的数值模拟成为一项艰巨的任务，从而为开发高效可靠的断裂力学模拟工具提供了主要障碍。该项目的目标是通过开发一种新的断裂力学理论和方法框架来应对这一挑战，这将特别允许在最近和即将到来的并行体系结构上对大规模问题进行数值模拟。为了实现这一目标，在建模方面，该框架将利用相场模型作为一种新的方法来表示裂纹界面。在离散化方法方面，我们将能够使用新的技术，如基于NURBS的ansatz空间。这些离散化方法的一个重要方面是，与传统的拉格朗日方法相比，它们具有优越的稳定性。特别是在大变形的情况下，这是一个相当大的优势。然而，这种稳定性是有代价的，因为NURBS需要一致地处理较大的面片，这在开发高效的自适应技术时会带来挑战。在这里，通过补丁或轻量级的自适应，我们将使用最新的发展结合了传统精化技术的灵活性和离散化的补丁视图，从而允许在大规模并行体系结构上设计高效的方法。除了新的基于相场的断裂方法外，我们还将扩展我们的新框架，以处理沿更大的内部裂纹界面的接触和摩擦效应。这样，我们的新框架将能够以一致的方式处理强非线性和非光滑效应。该项目将建立在工程、建模、计算科学和高性能计算方面的互补专业知识，以便为开发非传统有限元方法建立一个共同的基础，用于对经历有限变形的变分和热力学一致的多物理相场断裂模型进行大规模模拟。这个项目产生的新框架将提供一些新的和非标准的计算工具，这些工具将在气动和水力压裂的模拟过程中开发和测试。然而，最终的框架将以一种灵活的方式设计，这将使其应用范围超越水力压裂，从而从长远来看，可能成为新一类建模和模拟工具的基础。