CAREER: Microstructural Characterization and Modeling of Geomaterials

Washington State University, Pullman WA

Investigators

Abstract

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.