Particle rotations and energy dissipation during mechanical compression of granular materials

Research output: Contribution to journalArticle

Abstract

We present new in-situ measurements of particle rotations and energy dissipation during compression of 3D packings of stiff, frictional particles. Two confined, uniaxial compression tests with different degrees of lateral confinement are discussed. X-ray computed tomography and 3D X-ray diffraction were combined to provide inter-particle forces, slip and roll distances, twist angles, and energy dissipation at all inter-particle contacts. Each of these measured quantities followed exponential distributions above their respective mean values and power-law distributions below their mean values in both experiments. Changes in these distributions during experiments suggest that the quantities generally became more homogeneous with increasing overall sample stress. Contact roll and slip distances, twist angles, and energy dissipation were all more heterogeneous than inter-particle normal force magnitudes in both experiments. Energy dissipation due to inter-particle slipping accounted for 95% of the total energy dissipated in both experiments. Dissipation mechanisms at inter-particle contacts bearing more than the mean normal force were responsible for approximately 70% of each sample's dissipated energy at each load step, even though these contacts constituted approximately 40% of the total number of contacts.

Details

Authors
Organisations
External organisations
  • Johns Hopkins University
  • Lawrence Livermore National Laboratory
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Other Materials Engineering

Keywords

  • 3D X-ray diffraction, Energy dissipation, Granular materials, Inter-particle forces, X-ray tomography
Original languageEnglish
Pages (from-to)19-38
Number of pages20
JournalJournal of the Mechanics and Physics of Solids
Volume129
Publication statusPublished - 2019
Publication categoryResearch
Peer-reviewedYes