2019/02/08 by Kieran A. Murphy, Arthur K. MacKeith, Murphy, Kieran A. +5
Engineering · Environmental Science · Physics and Astronomy · #FOS: Physical sciences #Granular flow and fluidized beds #Landslides and related hazards #Soft Condensed Matter (cond-mat.soft) #Soil and Unsaturated Flow #cond-mat.soft
paper · pdf · doi:10.48550/arxiv.1902.03280
6 pages, 5 figures
openalex publication_date 2019/02/08 · arxiv created 2019/06/24 · arxiv updated 2019/06/26 · openalex created_date 2022/07/29 · openalex updated_date 2026/07/28
Both the shape of individual particles and their surface properties contribute to the strength of a granular material under shear. Here we show the degree to which these two aspects can be intertwined. In experiments on assemblies of 3D printed, convex lens-shaped particles, we measure the stress-strain response under repeated compressive loading and find that the aggregate's shear strength falls rapidly when compared to other particle shapes. We probe the granular material at mm-scales with X-ray computed tomography and μm-scales with high-resolution surface metrology to look for the cause of the degradation. We find that wear due to accumulated deformation smooths out the lens surfaces in a controlled and systematic manner that correlates with a significant loss of shear strength observed for the assembly as a whole. The sensitivity of lenses to changes in surface properties contrasts with results for assemblies of 3D printed tetrahedra and spheres, which under the same load cycling are found to exhibit only minor degradation in strength. This case study provides insight into the relationship between particle shape, surface wear, and the overall material response, and suggests new strategies when designing a granular material with desired evolution of properties under repeated deformation.