GOALI: Computational Multibody Dynamics: Addressing Modeling and Simulation Limitations in Problems with Friction and Contact

这个学术联络与工业（GOALI）计划项目的赠款机会汇集了威斯康星大学麦迪逊分校的研究小组和卡特彼勒的工程师团队，共同努力，旨在调查和实验验证能够通过计算机模拟预测大型动态系统时间演变的建模和数值求解方法。拟议的研究，开发和验证工作将增加计算机模拟在调查过程中的作用，如运输，混合和压实离散材料（粉末，颗粒，砾石，岩石）。尽管这些过程在广泛的工业中是相关的：例如，制造业、建筑业、农业、食品和药物，通过计算机建模和仿真对它们的研究目前提供的益处有限，除非问题的大小和/或分析的持续时间被大幅缩减，通常低于实际有用的限制。更好地理解大型多体系统的动力学是重要的，因为继水之后，离散介质在工业中被操纵得最多。此外，全球约有50%的贸易产品是颗粒状的，其制造、运输、加工、包装和混合构成了具有挑战性的问题，预计本研究的结果将提供有价值的见解。待研究的颗粒系统具有数百万到数十亿个组件，其集体行为由单个元件之间的摩擦接触相互作用主导。研究工作将集中在（1）调查两类解决方案的方法;即，Krylov子空间和原始对偶内点方法，以解决当前数值解的限制，源于实际应用的多尺度方面;（2）研究增广拉格朗日公式，以了解它们是否可以增强互补方法在多体动力学中的建模作用;（3）比较两类求解方法，即，在准确性、稳健性和可扩展性方面，对基于惩罚和基于互补的两种方法进行比较，以便汇编一套事实证据，总结每种方法的优缺点。

This Grant Opportunity for Academic Liaison with Industry (GOALI) Program project brings together a research group from the University of Wisconsin-Madison and a team of engineers from Caterpillar in a joint effort that aims at investigating and experimentally validating modeling and numerical solution methods capable of predicting through computer simulation the time evolution of large dynamic systems. The proposed research, development, and validation effort will increase the role that computer simulation plays in investigating processes such as transporting, mixing, and compacting discrete material (powders, grains, gravel, rocks). Although these processes are relevant in a broad spectrum of industries: e.g., manufacturing, construction, farming, food and drug, their investigation through computer modeling and simulation provides limited benefit today unless the problem size and/or duration of the analysis are drastically curtailed, often below practically useful limits. Better understanding the dynamics of large multibody systems is important since after water, discrete media are manipulated in industry the most. Moreover, about 50% of all traded products worldwide are in granular form and their manufacturing, transport, processing, packing and mixing pose challenging problems in which the outcomes of this research is anticipated to provide valuable insights. The granular systems to be investigated have millions to billions of components whose collective behavior is dominated by frictional contact interactions between individual elements. The research effort will concentrate on (1) investigating two classes of solutions methods; i.e., Krylov-subspace and Primal-Dual Interior Point methods, to address current numerical solution limitations that stem from the multiscale aspect of practical applications; (2) investigate augmented Lagrangian formulations to understand whether they can enhance the modeling role that complementarity approaches play in multibody dynamics; and (3) compare two classes of solution methods; i.e., penalty-based and complementarity-based, in terms of accuracy, robustness and scalability in order to compile a factual body of evidence that summarizes the advantages and disadvantages of each approach.