Using Mixed Discrete-Continuum Representations to Characterize the Dynamics of Large Many-Body Dynamics Problems

使用混合离散连续体表示来表征大型多体动力学问题的动力学

• 批准号: 1635004
• 负责人: Dan Negrut
• 金额: $ 40万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1635004&HistoricalAwards=false
• 关键词: Using; Mixed; Discrete; Continuum; Representations

The goal of this project is to understand how computer simulation can be used to predict the motion of large systems of bodies interacting with each other through friction and contact. Studying these so-called "many-body dynamics problems" has theoretical and practical relevance in several disciplines (physics, chemistry, astronomy, geomechanics), industries (pharmaceuticals, food processing, farming, manufacturing, construction, mining), and engineering applications (additive manufacturing, nanoparticle self-assembly, robotics, ground vehicle mobility). In terms of educational and outreach impact, initiatives undertaken as part of this project will (i) promote the discipline of Computational Science at middle and high-school levels via a "The Science Behind Video Gaming" short course and a residential summer program, respectively; (ii) update and expand curricula in two graduate courses on high performance computing and advanced computational dynamics; (iii) expand a biannual advanced computing forum that facilitates transfer of technology; and, (iv) provide training via a Master of Engineering distance learning program for practitioners who need to analyze, process, and solve problems using information generated by the growing use of data collection in engineering design and industrial operations.The research effort will focus on investigating techniques that facilitate a discrete-continuum dual representation in the simulation of many-body dynamics problems. The fundamental question answered is how should one handle parts of a many-body dynamics problem using a continuum formalism so that the new mixed discrete-continuum representation manages to preserve the dynamics of the original problem? Also, how should a continuum representation be fine-grained into a discrete one, and conversely, what techniques should be used to coarse-grain a discrete representation into a continuous one? Mechanical engineering expertise (dynamics of many-body systems, solid mechanics, plasticity), applied math techniques (meshless methods for solving partial differential equations, optimization methods), and computer science components (machine learning, software engineering) will combine in a coordinated effort to solve the stated problem. In this context, the goal of this project is to (a) establish a systematic methodology for producing rheologies that, when embedded in a continuum mechanics model, produce a solution that is close to that of a large discrete many-body dynamics problem; and (b) use this methodology to understand whether there are rheologies that have a universal attribute; i.e., that are applicable to all, or a large spectrum of, many-body dynamics problems. In this context, a rheology is regarded as a methodology that ties at microscale the dynamics/flow of a continuum to the forces acting on it. The research plan is built around the idea of augmenting physical insights with a machine learning process that uses large amounts of data generated by fully-resolved, many-body dynamics solutions to produce rheology candidates.

该项目的目标是了解计算机模拟如何用于预测通过摩擦和接触相互作用的大型物体系统的运动。研究这些所谓的“多体动力学问题”在多个学科（物理学，化学，天文学，地质力学），工业（制药，食品加工，农业，制造业，建筑业，采矿业）和工程应用（增材制造，纳米粒子自组装，机器人技术，地面车辆移动性）中具有理论和实践意义。在教育和外联影响方面，作为该项目一部分采取的举措将：㈠分别通过“视频游戏背后的科学”短期课程和住宿暑期方案，在初中和高中一级促进计算科学学科; ㈡更新和扩大关于高性能计算和高级计算动力学的两门研究生课程的课程; ㈢扩大一年两次的促进技术转让的高级计算论坛;以及，（iv）通过工程远程学习硕士课程为需要分析，处理，并利用工程设计和工业运营中越来越多地使用数据收集所产生的信息来解决问题。研究工作将集中在在调查技术，促进离散连续双表示在多体动力学问题的模拟。回答的基本问题是，应该如何处理一个多体动力学问题的一部分，使用连续形式主义，使新的混合离散连续表示管理，以保持原来的问题的动力学？此外，如何将连续表示细化为离散表示，相反，应该使用什么技术将离散表示粗粒度化为连续表示？机械工程专业知识（多体系统动力学，固体力学，塑性），应用数学技术（求解偏微分方程的无网格方法，优化方法）和计算机科学组件（机器学习，软件工程）将结合联合收割机协调解决所述问题。在此背景下，本项目的目标是：（a）建立一个系统的方法，用于产生流变学，当嵌入连续介质力学模型时，产生一个接近大型离散多体动力学问题的解决方案;（B）使用此方法来了解是否存在具有普遍属性的流变学，即，适用于所有或大范围的多体动力学问题。在这种情况下，流变学被认为是一种方法，在微观尺度上的连续体的动力学/流动的联系，以其上的力。研究计划是围绕着增强物理洞察力的机器学习过程，使用大量的数据产生的完全解析，多体动力学解决方案，以产生流变学候选人的想法。

项目成果

Posing Multibody Dynamics With Friction and Contact as a Differential Complementarity Problem

• DOI: 10.1115/1.4037415
• 发表时间: 2018
• 期刊: Journal of Computational and Nonlinear Dynamics
• 影响因子: 2
• 作者: D. Negrut;R. Serban;A. Tasora

Multibody dynamics vs. fluid dynamics: two perspectives on the dynamics of granular flows

多体动力学与流体动力学：颗粒流动力学的两种观点

• 发表时间: 2020
• 期刊: Journal of computational and nonlinear dynamics
• 影响因子: 2
• 作者: Milad Rakhsha, Conlain Kelly

On the use of multibody dynamics techniques to simulate fluid dynamics and fluid–solid interaction problems

• DOI: 10.1007/s11044-021-09784-y
• 发表时间: 2021-03
• 期刊: Multibody System Dynamics
• 影响因子: 3.4
• 作者: Milad Rakhsha;Lijing Yang;Wei Hu;D. Negrut