Applications of computerized tomography to study microstructures of granular materials

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:175254

Lee, X ^[1]

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1. Federal Aviation Administration, Atlantic City International Airport, NJ (United States)

Properties of granular materials are greatly influenced by their internal packing structures. The correlation between microstructure changes and overall material behavior have been extensively studied in recent years by utilizing computational techniques. This paper presents a novel experimental method to characterize packing structure changes of granular materials. This method can be applied to determine microstructure parameters describing mechanical properties of granular materials required in micromechanical modeling. Important parameters including volume fractions, particle arrangements, and contact geometry, as well as their changes under loads, can now be identified experimentally for the first time. The developed method utilizes a high-resolution X-ray computerized tomography (CT) machine to acquire cross-sectional images of a material sample, which was about three-inches in diameter and six-inches long, made of 6-mm glass beads mixed with asphalt as binder material. Multiple cross-sectional images were obtained along the axial direction. Numerical algorithms were developed to analyze these CT images to determine the three-dimensional (3D) packing structures of the sample scanned. Microstructure parameters of the sample such as particle sizes, coordination numbers, and contact orientations as well as asphalt binder structures were studied. Packing structure changes of the sample under load were also obtained by using a special loading device. Correlation between the macroscopic behavior (stress-strain relations) and corresponding microscopic packing structure changes was also analyzed. The present study demonstrates the great potential of the applications of CT technology on quantifying actual microstructure parameters of granular materials, which cannot be done otherwise.

• OSTI ID: 175254
• Report Number(s): CONF-950686--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
COMPUTERIZED TOMOGRAPHY
GRANULAR MATERIALS
IMAGES
MECHANICAL PROPERTIES
MICROSTRUCTURE
RESOLUTION