On Acquisition Parameters and Processing Techniques for Interparticle Contact Detection in Granular Packings Using...

Area of Science:

• Geomechanics
• Materials Science
• Imaging Science

Background:

• X-ray computed tomography (XCT) is vital for non-destructive analysis of soil and rock in geomechanics.
• Accurate measurement of interparticle contacts is essential for soil behavior modeling.
• Conventional XCT methods often overestimate contact parameters due to image artifacts.

Purpose of the Study:

• To systematically assess the impact of XCT acquisition parameters on interparticle contact detection accuracy.
• To compare conventional and deep learning-based image segmentation for contact analysis.
• To propose optimized workflows for precise microfabric characterization using XCT.

Main Methods:

• Synchrotron XCT applied to hexagonal close-packed glass pellets.
• Systematic variation of acquisition parameters: number of projections, exposure time, rotation range.
• Evaluation of global thresholding and U-Net segmentation, followed by local contact refinement routines.

Main Results:

• Demonstrated significant influence of XCT acquisition parameters on contact detection accuracy.
• Highlighted limitations of conventional methods and potential of U-Net segmentation.
• Quantified the overestimation of contacts by standard image processing techniques.

Conclusions:

• Optimized XCT acquisition and processing workflows are necessary for accurate interparticle contact detection.
• Advanced segmentation techniques like U-Net show promise for improved microfabric analysis.
• Findings provide a foundation for more reliable soil behavior modeling informed by precise geomechanical data.