ITR/AP (ENG): A Framework-Based Finite Element Approach to Solving Current and Future Multi-physics Problems in Geomaterials

地质材料，即土壤和岩石，在自然界中非常普遍，它们是许多工程问题和解决方案的一部分。所有土木工程结构最终都必须由土壤或岩石支撑。在地震等灾难性荷载事件中，土壤和岩石在土木工程结构（如建筑物、桥梁、水坝、堤坝和渡槽）的行为中起着不可或缺的作用。土壤也是环境问题和解决方案的重要组成部分。石油碳氢化合物的生产涉及到深层的岩石。岩土材料是一种多相多孔介质，由固体骨架和孔隙空间内的多种流体组成。岩土材料在各种荷载作用下表现出高度非线性和滞回特性。传统上，工程师将上述过程分开处理，并经常简化假设。随着信息技术（IT）在可扩展并行计算机算法、分布式计算机系统、高速网络和可视化等领域的最新进展，现在有可能实现一个统一的地理分析工具，用于解决涉及地理材料的当前和未来问题，其中不需要进行不必要的简化假设，并且可以分析真实世界系统的完整三维模型。实现这一统一分析工具的关键组件是基于框架的有限元应用程序。框架表示用于在某些公共领域中构建应用程序的公共软件组件的集合。使用框架背后的基本前提是认识到在编写应用程序时必须完成的一组公共任务。这些任务可以从应用程序代码中分离出来，并收集到一组组件中。从本质上讲，框架将物理问题与解决该问题的计算机科学方面分离开来。该项目旨在通过俄克拉何马大学（OU）、TeraScale有限责任公司和劳伦斯利弗莫尔国家实验室的三方合作，利用基于框架的有限元应用程序开发一种可扩展的并行地理分析工具。这个工具和底层框架将很容易为学术界和工业界所用，而成本只是类似单片代码的一小部分。该分析工具最初将能够分析干燥，非饱和和饱和土壤（流体流动和固体骨架变形）的静态和动态行为。然而，与专有单片代码的“封闭”体系结构相反，框架的“开放”体系结构将为用户提供易于扩展的功能，以便在地理材料中包含其他多物理场行为。所得工具将首先使用饱和和非饱和土壤中简单问题的封闭形式解进行验证。然后将使用离心机模型测试结果对该工具进行边值问题验证。将进行计算实验来测试分析工具在各种分布式和并行计算环境下的能力。在教育方面，TeraScale框架将被整合到《有限元法入门》等课程中，从而向学生介绍这种工程分析的新范式和可扩展并行计算等IT概念。使用俄克拉荷马州的OneNet，俄克拉荷马州的高中生将有机会操作和查看拟议的地理分析工具的结果，并通过互联网进行一些简单的分析。看到令人兴奋的问题并与之互动，比如大坝的地震负荷，将有助于招收更多的高中生学习科学和工程。期望所开发的地理分析工具不仅能使分布式计算等信息技术的最新进展广泛应用于工程界，而且还能以协同的方式推进信息技术研究本身的各个方面。例如，提议的地理分析工具将作为评估当前和未来分布式计算设施效率的测试用例。

Geomaterials, i.e., soil and rock, are quite prevalent in nature and they are part of numerous engineering problems and solutions. All civil engineering structures have to be ultimately supported on soils or rocks. Soils and rocks play an integral part in the behavior of civil engineering structures such as buildings, bridges, dams, levees, and aqueducts during catastrophic loading events such as earthquakes. Soils are also major part of environmental problems and solutions. Production of petroleum hydrocarbons involves rocks at large depths. Geomaterials are multiphase porous media consisting of a solid skeleton and number of fluids within the pore space. Geomaterials exhibit highly nonlinear and hysteretic behavior during various loading situations. Traditionally the engineers have treated the above-mentioned processes separately and often with simplifying assumptions. With the recent advances made in Information Technology (IT) in areas such as scalable parallel computer algorithms, distributed computer systems, high speed networks, and visualization it is now possible to realize a unified geo-analysis tool for solving current and future problems involving geomaterials where unnecessary simplified assumptions need not be made and the full 3-D model of a real world system can be analyzed.A key component in achieving this unified analysis tool is a framework-based finite element application. A framework represents a collection of common software components for building applications in some common domain. The basic premise behind the use of a framework is the recognition of a common set of tasks that must be accomplished in writing the applications. These tasks can be factored out of the application codes and collected into a single set of components. Essentially a framework separates physics of a problem from the computer science aspects of solving that problem. This project is directed toward developing a scalable, parallel geo-analysis tool using a framework-based finite element application in a three-way collaboration between the University of Oklahoma (OU), the TeraScale, LLC, and the Lawrence Livermore National Laboratory. This tool and the underlying framework will be readily available to the academic community and industry at a fraction of the cost of similar monolithic codes. This analysis tool will initially be capable of analyzing static and dynamic behavior of dry, unsaturated, and saturated soils (fluid flows and solid skeleton deformations). However, as opposed to the "closed" architecture of the proprietary monolithic codes, the "open" architecture of the framework will provide users with easy extendibility to include other multi-physics behavior in geomaterials. The resulting tool will be verified first using closed-form solutions of simple problems in saturated and unsaturated soils. Then the tool will be validated using centrifuge model tests results for boundary value problems. Computational experiments will be conducted to test the analysis tool's capabilities under various distributed and parallel computing environments. On the educational front the TeraScale framework will be integrated into courses such as the Introduction to Finite Element Method and thereby introducing students to this new paradigm in engineering analysis and IT concepts such as scalable parallel computing. Using Oklahoma's OneNet, High School students in Oklahoma will be provided an opportunity to manipulate and view the results from the proposed geo-analysis tool as well as conduct some simple analyses through the Internet. Seeing and interacting with visualization of exciting problems such as the earthquake loading of a dam will help recruit more High School students to science and engineering.It is expected that the geo-analysis tool developed will not only make the current advances in IT, such as the distributed computing, widely accessible to engineering community, but also advance various aspects of IT research itself in a synergetic manner. For example, the proposed geo-analysis tool will serve as a test case for evaluating the efficiency of current and future distributed computing facilities.