Investigating crushing-induced particle shape change in granular material

Abstract

High-pressure uniaxial compression tests were conducted under strain-controlled conditions using spherical glass beads. The study focused on investigating the compression behavior and particle fragmentation phenomena, particularly observing changes in particle size and shape resulting from fragmentation. The examination of particle shape, specifically sphericity and roundness, was emphasized. The samples comprised glass beads with uniform particle size and shape initially. It was observed that pressures exceeding 20MPa triggered particle fragmentation, leading to significant compression behavior. Notably, a softening phenomenon characterized by rapid fluctuations in compressive stress, despite a monotonic increase in strain, was observed during fragmentation. This phenomenon indicates the particles' catastrophic failure, unable to withstand the contact forces they previously sustained. Observations of particle shape revealed trends toward asymptotic distributions in cumulative curves for particle size, sphericity, and roundness. Moreover, changes in the cumulative curve of roundness were more pronounced compared to particle size and sphericity.

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