权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Advanced fracture mechanics modelling to understand earth-environment interactions

先进的断裂力学建模以了解地球与环境的相互作用

基本信息

批准号：
2446853
负责人：
金额：
--
依托单位：
Imperial College London
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2020
资助国家：
英国
起止时间：
2020 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2446853
关键词：
Advanced fracture mechanics modelling understand

项目摘要

The project aims to develop a new generation of physically-based models for rock fracture, with applications in mining, excavation and prediction of geohazards. The civil and mining engineering industries have many energy-intensive processes that involve fragmenting rocks. Mining accounts for up to 6% of world energy consumption, with rock comminution (grinding, crushing and cutting) being responsible for half of this vast energy expenditure. Rock excavation, either through mechanical drilling or by blasting, constitutes the largest source of energy consumption in a wide range of civil engineering applications, from tunnels to buildings. The emergence of low-energy techniques for rock fracture could have a major impact on sustainability and global warming, and is necessary because of economic competitiveness, tougher environmental regulations, and continuously growing global energy demand. Major improvements in rock comminution procedures are hindered by the lack of understanding of the mechanics of micro-cracks and their overall response to applied loading. Because of the large scales involved, deformation and failure in rock engineering have been traditionally modelled through empirical approaches. However, these phenomenological models require extensive calibration and have a regime of applicability that is limited to scenarios resembling the calibration schemes. Predictive modelling requires an explicit connection with the underlying microstructure. The essential ingredients necessary to develop physically-based models that will significantly shift the knowledge frontier are now available. First, recent major advances in high resolution measuring techniques - particularly, micro X-ray computerised tomography and Digital Volume Correlation - provide a direct connection to the microstructure and enable cracking pattern characterisation. Secondly, relevant features of the microstructure can be incorporated into large-scale simulations as a result of larger computational resources and the development of robust numerical methods to capture crack fragmentation. The project will combine theoretical, experimental and numerical endeavours. On the theoretical side, a new microstructurally-informed framework will be developed, capable of delivering predictions from macro and micro nominal material properties, as opposed to empirical parameters. The aim is to build upon the success of the "micromechanics revolution" that has significantly enhanced our understanding and modelling of metals and ceramics. Experimental observations will be critical in identifying the micromechanisms dominating micro-crack growth and coalescence. On the numerical side, the model will be implemented in a finite element setting and comparisons will be conducted with experiments and discrete element method (DEM) simulations. The model will be employed to identify crack patterns that will allow designing low-energy comminution procedures. Not only will loading criteria be established for minimizing friction but also crack branching will tailor the mineral size as produced by each process. By giving insight into the mechanisms at play, the project will benefit the understanding and modelling of other geological applications, such as hydraulic fracture and earthquake rupture.

该项目旨在开发新一代基于物理的岩石破裂模型，应用于采矿、挖掘和地质灾害预测。土木工程和采矿工程行业有许多涉及破碎岩石的能源密集型过程。采矿业占世界能源消耗的6%，其中岩石粉碎(研磨、粉碎和切割)占这一巨大能源消耗的一半。在从隧道到建筑物的广泛土木工程应用中，通过机械钻探或爆破进行的岩石开挖是最大的能源消耗来源。低能量岩石破裂技术的出现可能会对可持续性和全球变暖产生重大影响，这是必要的，因为经济竞争力、更严格的环境法规以及不断增长的全球能源需求。由于缺乏对微裂纹的机理及其对外加载荷的整体响应的了解，岩石粉碎程序的重大改进受到阻碍。由于所涉及的规模很大，岩石工程中的变形和破坏传统上是通过经验方法来模拟的。然而，这些现象学模型需要广泛的校准，并且具有仅限于类似校准方案的情景的适用制度。预测性建模需要与潜在的微观结构建立明确的联系。开发将显著改变知识前沿的基于物理的模型所需的基本要素现在已经可用。首先，高分辨率测量技术的最新重大进展--特别是微型X射线计算机层析成像和数字体积相关技术--提供了与微观结构的直接联系，并使裂纹模式表征成为可能。其次，由于更大的计算资源和捕捉裂纹断裂的稳健数值方法的发展，微观结构的相关特征可以被纳入大规模模拟中。该项目将结合理论、实验和数值方面的努力。在理论方面，将开发一个新的微观结构信息框架，能够根据宏观和微观名义材料属性而不是经验参数进行预测。其目的是在“微观力学革命”的成功基础上再接再厉，这场革命极大地提高了我们对金属和陶瓷的理解和建模。实验观察对于确定主宰微裂纹扩展和聚合的微观机制至关重要。在数值方面，模型将在有限元环境下实现，并将与实验和离散单元法(DEM)模拟进行比较。该模型将被用来识别裂纹模式，从而设计出低能量的粉碎程序。不仅将建立加载标准，以最大限度地减少摩擦，而且裂缝分支将根据每个工艺产生的矿物尺寸进行调整。通过深入了解其作用机制，该项目将有助于理解和模拟其他地质应用，如水力压裂和地震破裂。