How the Cookie Crumbles: Data Analysis for Experimental Granular Materials Research

ORAL

Abstract

Granular materials are characterized as a conglomeration of macroscopic particles which experience a loss of energy upon interaction, while being large enough to avoid thermal motion fluctuations. Despite centuries of study, their behavior is still mysterious. Theoretical work has traditionally focused on spheres and hard ellipsoids rather than simple polygons or polyhedra. Previous experimental research on polygons created from lattices of welded ball bearings had indicated a link between angle and density in two dimensions immediately prior to an avalanche. The goal of this project was to confirm those findings and attempt to determine what portion of the material was responsible for the correlation. Code was written to analyze photos of a rotating frame containing a sample granular material, making it possible to find density and angle for regions of arbitrary size and calculate correlations from them. Correlations for various granular shapes were most visible when taken over large regions and decreased in smaller regions as noise became dominant with one notable exception.

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Authors

  • Victoria Winbow

    Trinity University

  • Nilanjan Das

    Dept. of Physics, ESFM-IPN, Mexico City, Dept. of Physics, The University of Texas at El Paso, Texas A\&M University, Southeast Missouri State University, Departamento de Fisica, FCEN, Universidad de Buenos Aires, Nunez, Argentina, Cyclotron Institute, Texas A\&M University, University of Houston, Denison U., Advanced Space Propulsion Laboratory, AdAstra Rocket Company, Texas Tech University, Department of Chemistry and Biochemistry, Texas State Unv. - San Marcos, Department of Physics, Texas State Unv. - San Marcos, Rice U., Texas State University - San Marcos, Freescale Semiconductor, Inc., Varian Semiconductor Equipment Associates, Gloucester, MA, University of North Texas, Denton, TX, National Insitute of Standards \& Technology, Gaithersburg, MD, James Madison University, Harrisonburg, VA, Texas A\&M University, College Station, TX, Hong Kong University of Science and Technology; Texas Center for Superconductivity and Advanced Materials, University of Houston, Texas Center for Superconductivity at the University of Houston, University of Houston, University of Idaho, Department of Physics, Istanbul Technical University, University of California at Davis, Physics Department, University of South Florida, FL 33620, Physics Department, Texas A\&M University, TX 77843, Center for Studies in Statistical Mechanics and Complex Systems, The University of Texas at Austin, Rice University, TcSUH, University of Houston, Lawrence Berkeley National Laboratory, Hong Kong University of Science and Technology, Institute of Solid State Physics, Bulgarian Academy of Sciences, Hong Kong University of Science and Technology; Texas Center for Superconductivity, University of Houston; Lawrence Berkeley National Laboratory, Texas Center for Superconductivity, University of Houston