CAREER: Microstructural Characterization and Modeling of Geomaterials

微观结构表征和建模对于理解工程材料的宏观行为是必不可少的。它经常被用来设计具有定制微结构的新材料，获得多尺度连续介质模型的参数，并在材料微观结构水平上模拟工程过程。微结构表征技术极大地促进了对许多工程材料，如金属、陶瓷和复合材料的理解。这一学院早期职业发展(CALEAR)研究和教育项目提供了一种将岩土材料的微结构与其宏观性能联系起来的新途径。其重点是开发一种量化三维岩土材料微结构及其对流体流动特性和定向渗透率的影响的方法。这些特性对岩土材料中的几个现象有重要影响，如饱和土壤的稳定性、污染物在土壤中的传输、石油在岩石中的传输以及路面的使用性能。所提出的研究很好地平衡了表征岩土材料三维微结构的实验方法、数值模拟和计算机模拟。X射线计算机层析成像(CT)将被用于捕捉岩土材料的三维微结构。计算流体力学将被用来开发由X射线CT图像定义的材料微结构边界条件内的流体流动方程的数值解。实验测量将用于验证所开发的模型和计算机模拟。这项研究的结果将为了解微结构对岩土材料宏观性能的影响提供独特的见解。它将提供一种预测材料渗透率和流体流动特性的基本方法，最终导致地球系统的有效设计。这些研究活动将被整合到一个教育计划中，该计划通过本科生开展的以团队为导向的项目和研究生课程开发，将实验无损技术、图像分析、数值模拟和计算机模拟的最新进展纳入学术课程。还将建立一个暑期教育计划，重点是高中生和从其他大学招聘的学生的参与，重点是工程学中代表性不足的群体。学生将能够将微观结构属性与宏观响应联系起来，并通过计算机模拟可视化微观结构对材料行为的影响。该项目包括一个管理计划，以确保实现研究、教育和推广目标。它涉及一个由来自学术界、研究机构和政府机构的多学科个人组成的咨询委员会。该委员会的作用将是提供技术咨询，促进结果的传播，并确保向教育和专业组织公布结果。该委员会的另一个作用将是促进代表人数不足的学生群体的参与。

Microstructure characterization and modeling are essential for the understanding of the macroscopic behavior of engineering materials. It is often used to design new materials with tailored microstructures, obtain parameters for multiscale continuum models, and simulate engineering processes at the material microstructure level. Microstructure characterization techniques have significantly advanced the understanding of many engineering materials such as metals, ceramics, and composites.This Faculty Early Career Development (CAREER) research and education project offers a novel approach for linking the geomaterials microstructure to their macroscopic properties. It focuses on developing an approach to quantify the three-dimensional geomaterial microstructure and its influence on fluid flow characteristics and directional permeability. These properties have significant impact on several phenomena in geomaterials such as the stability of saturated soils, contaminant transport in soils, oil transport in rocks, and the performance of pavements. The proposed research is well balanced between experimental methods for characterizing the 3-D microstructure of geomaterials, numerical modeling, and computer simulation. X-ray computed tomography (CT) will be used to capture the three-dimensional microstructure of geomaterials. Computational fluid dynamics will be used to develop a numerical solution to the fluid flow equations within the boundary conditions of the material microstructure as defined by the X-ray CT images. Experimental measurements will be used to verify the developed models and computer simulations. The outcome of this research will provide unique insight into the influence of the microstructure on the macroscopic properties of geomaterials. It will offer a fundamental approach for predicting material permeability and fluid flow characteristics that will ultimately lead to effective design of geosystems.These research activities will be integrated in an educational program that incorporates recent advances in experimental non-destructive techniques, image analysis, numerical modeling, and computer simulation into the academic curriculum through team-oriented projects conducted by undergraduate students, and graduate course development. A summer educational program will also be established that focuses on the participation of high school students, and those recruited from other universities with emphasis on underrepresented groups in engineering. Students will be able to link the microstructure properties to the macroscopic response, and visualize the influence of the microstructure on the material behavior through computer simulations.The project includes a management plan to ensure achieving the research, educational and outreach objectives. It involves an advisory committee consisting of multidisciplinary individuals from academia, research institutions, and government agencies. The role of this committee will be to offer technical advice, facilitate dissemination of the results and ensure exposure of the findings to educational and professional organizations. An additional role of this committee will be to facilitate the involvement of underrepresented student groups.