GGS - Modelling forces and stresses in gigantic granular systems for coastal engineers

GGS - 为沿海工程师模拟巨大颗粒系统中的力和应力

基本信息

批准号：
EP/H030123/1
负责人：
John-Paul Latham
金额：
$ 60.63万
依托单位：
Imperial College London
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2010
资助国家：
英国
起止时间：
2010 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FH030123%2F1
关键词：
GGS Modelling forces stresses gigantic

项目摘要

The Research Team is based within the Applied Modelling and Computation Group (AMCG) at Imperial in the Department of Earth Science and Engineering. The industrial partners, Sogreah Consultants, and Baird & Associates, are world leaders in Coastal Engineering and have committed considerable financial support. This project exploits the VGW EPSRC project in which numerical models were developed.To meet this century's challenge of extensive and accelerating future coastal change, society will expect coastal engineers to design resilient structures to hold the line against flood and erosion where it is deemed necessary. The first choice construction material and design approach for such structures will often be to use armour layers of massive rocks or concrete units. Currently, designers do not understand the details of how they work, relying heavily on empirical methods. This project will reveal fundamental mechanisms that cause disintegration of these rubble mound coastal structures and breakwaters. With our further enhanced simulation tools we will re-create the construction process, examine inherent heterogeneity, explore unit shapes and their interaction with under-layer rock geometry, examine scale effects, and use vibration and other proxies for wave disturbance, all to study block motion, contact force and stress heterogeneity and risk of concrete unit breakages.The aims are to:(1) Promote a shift in design approach from empirical to scientifically-determined damage and breakage probabilities. This requires modelling the solid geometry together with both the static and transient dynamic stress states within gigantic granular systems of complex-shaped concrete units and rock armour used in coastal structures and breakwaters, during construction, when at rest and as perturbed by external forces. (2) Extend the stress and deformation analysis tools of our world-leading 3D FEMDEM modelling technology that combines the multi-body interaction and motion modelling (i.e. Discrete Element Model, DEM) with the ability to model internal deformation of arbitrary shape (Finite Element Model, FEM) to the point where they can be readily harnessed to deliver a more fundamental understanding of a wide range of environmental and industrial problems.The layers of concrete units and rocks targeted in this coastal research are an extreme case of particulate or granular media intensively studied by physicists, with solid-like behaviour dominating but potentially fluid-like behaviour possible, should they become unravelled in a storm. Scientists have long been able to see stresses in photo-elastically deformed grain pack experiments using any 2D grain shapes, but have had no such property or tool to interrogate our real-world 3D granular systems. This is all about to change following research by the PI and co-workers - the development of a generic 3D computer model based on FEMDEM developed under our VGW EPSRC grant. No other model (presented in the literature) handles multi-body dynamics of complex-shaped deformable particles with greater accuracy, capturing the stress components everywhere in time and space. This project will bring fresh modelling capability to both fundamental science and engineering applications of granular materials. Information about temporal and spatial heterogeneity of stress will become available to underpin the workings at the heart of our currently limited understanding of granular material behaviour that is so vexing the physicists.Applications of numerical models to loading and collapse of silos, mineral and powder processing/handling, avalanching, and geotechnics have all been attempted using DEM. Upgrading DEM to FEMDEM, taking account of deformability, dynamics and the angularity/complexity of particle shape in these multi-body systems will significantly improve simulations, extending applications to unprecedented fields such as biomechanics and nuclear systems, too numerous to list here.

该研究团队位于地球科学与工程系帝国的应用建模和计算小组（AMCG）中。工业伙伴，Sogreah顾问和Baird＆Associates是沿海工程领域的世界领导者，并提供了大量的财政支持。该项目利用了开发数值模型的VGW EPSRC项目。要应对本世纪的广泛和加速未来的沿海变化挑战，社会将期望沿海工程师设计有弹性的结构，以抵抗必要的洪水和侵蚀。此类结构的首选建筑材料和设计方法通常是使用大型岩石或混凝土单元的装甲层。目前，设计师不了解其工作方式的细节，严重依赖经验方法。该项目将揭示基本机制，这些机制导致这些瓦砾丘陵结构和防波堤的瓦解。借助我们进一步增强的模拟工具，我们将重新创建施工过程，检查固有的异质性，探索单位形状及其与层岩石下岩石几何形状的相互作用，检查规模效应，并使用振动和其他代理来进行波浪干扰，所有这些都可以研究阻止运动，接触力和压力异质性和促进混凝土单位的风险，以促进混凝土的促进。损坏和断裂概率。这需要对固体几何形状进行建模，以及在沿海结构和防波堤上使用的巨大颗粒状混凝土单元和岩石装甲内的静态和瞬态动态应力状态，在施工期间，在休息和外部力量扰动时。（2）扩展我们世界领先的3D FemDem建模技术的压力和变形分析工具，结合了多体相互作用和运动建模（即离散元素模型，DEM，DEM）的能力，并能够建模任意形状的内部变形（有限元模型，fem），并能够轻松地将它们范围内的层次和工业范围内的范围划分为层次，并在范围内进行整体范围的范围。在这项沿海研究中，是由物理学家深入研究的颗粒或颗粒状培养基的极端情况，如果在风暴中脱离了固体样的行为，则可以主导但潜在的类似流体的行为。长期以来，科学家能够使用任何2D谷物形状看到光线形变形的谷物包实验的压力，但没有这种特性或工具来询问我们的现实世界3D粒状系统。 PI和同事的研究后，这一切都将改变 - 基于我们VGW EPSRC赠款开发的FEMDEM的通用3D计算机模型的开发。没有其他模型（文献中呈现）处理具有更高精度的复杂形状可变形颗粒的多体动力学，从而捕获了时间和空间中各地的应力成分。该项目将为颗粒材料的基本科学和工程应用带来新的建模能力。有关压力的时间和空间异质性的信息将获得我们当前对颗粒物材料行为的理解的核心，这是对物理学家如此烦恼的核心。考虑到这些多体系统中粒子形状的可变形性，动力学和角度/复杂性，将DEM升级到FEMDEM将显着改善模拟，从而将应用扩展到前所未有的领域，例如生物力学和核系统，在此处列出了太多。