Granular media simulations are important for many industrial and geophysical applications. Capturing the damage of individual grains leads to an effective model for granular media. The discrete element method (DEM) introduced by Cundall and Strack, provides one framework for granular simulation assuming that particle shapes are rigid. While DEM-based approaches capture the rigid motion of the particle boundaries they do not account for the deformation of individual grains. In addition DEM does not capture complex damage propagation based on each particle’s geometry, nor the effects of pre-cracked particles.Peridynamics is a nonlocal reformulation of continuum mechanics and leads to natually occuring fracture as an emergent behavior. Peridyamics has been used to model intra-granular force in addition to contact force between grains.&nbsp; Behzadinasab et., al. [1],&nbsp; have studied shockwave propagation. Zhu and Zhao [2] has used a peridynamics approach to study crushing piles of sand.&nbsp; Jha et. al. [3], combined DEM with peridynamics (PeriDEM) to the study of granular flows. In this talk we add to the discussion of new combined peridynamic and DEM based techniques.This approach allows us to incorporate effects of both particle deformation and particle damage in studies of the overall behavior of particle beds such as pavements or soils. In this work, we address the technical challenges associated with bulk simulation of arbitrary shaped particles. We propose a numerical correction to the Coulomb’s friction force law that eliminates undesired numerical oscillation from the simulation. Unlike earlier approaches, we consider a Kelvin-Voigt model for damping that incorporates damping at the node level. We have studied the mechanical response of the bulk of a particle with and without fracture including arbitrary shapes. Several numerical improvements for particle bed simulations are carried out. The particle bed is generated from a mesh of the discretization of the interior of the container by solving an optimization problem. The contact between particle and the wall boundaries computed analytically to speed up the simulations. A series of numerical experiments on particle beds involving arbitrary particle shapes are performed. First, we consider a particle bed settling under gravity. The reaction force on the wall of the particle containers is computed. Next, various particle roundness is considered and the effect of packing ratio and the average wall contact force is studied for various particle shapes. We then go on to show the behavior of granular beds made from cross shaped grains, rectangular where the individual grains subject to fracture and damage as well as elastic deformation. We investigate energy absorbing beds as well as particle beds for use as pavements.References[1]. M. Behzadinasab, T. J. Vogler, A. M. Peterson, R. Rahman, and J. T. Foster. Peridynamics Modeling of a Shock WavePerturbation Decay Experiment in Granular Materials with Intra-granular Fracture.J. dynamic behavior mater., 4(4):529–542, Dec. 2018[2]. Zhu, F. &amp; Zhao, J. (2019).Géotechnique 69, No. 6, 526–540.[3]. P. K. Jha, P. S. Desai, D. Bhattacharya, and R. Lipton. Peridynamics-based discrete element method (PeriDEM) modelof granular systems involving breakage of arbitrarily shaped particles.Journal of the Mechanics and Physics of Solids,151:104376, June 2021.

Modeling and Simulaion of Granular Media Using Peridynamics

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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