Statistical distributions of the elastic moduli of particle aggregates at the mesoscale. (May 2020)

• Record Type: Journal Article
• Authors: Pekmezi, Gerald; Littlefield, David; Chareyre, Bruno
• Is Part Of: International journal of impact engineering. Volume 139(2020)
• Publication Date: 2020-05
• Subjects: DEM -- Mesoscale -- Hill condition -- Microboundaries -- Elastic moduli;Homogenization -- Eglin sand -- Statistical mechanics; Impact -- Periodicals; Shock (Mechanics) -- Periodicals; Impact -- Périodiques; Choc (Mécanique) -- Périodiques; Impact; Shock (Mechanics); Periodicals; 620.1125
• DOI: 10.1016/j.ijimpeng.2019.103481
• Languages: English
• ISSNs: 0734-743X

Abstract

Highlights: The Discrete Element Method is used as a mesoscale modeling method for sand. The mesoscale modeling considers randomness through statistical mechanics. Upper and lower bounds for elastic moduli of Eglin sand are computed at the mesoscale. Abstract: This study introduces an important development in the modeling of granular media. A recently-developed real-time interface tracking algorithm for particle-based simulation methods can be used to study the bounds of discrete particle aggregates such as sand. The interface tracking algorithm uses an advanced surface extraction technique based on the alpha shape paradigm of computational geometry. When used concurrently with particle-based methods, this algorithm is capable of tracking the evolution of the simulation boundaries and applying accurate micro-boundary conditions on them. The micro-boundary conditions may be of Dirichlet type, Neumann type, or mixed-orthogonal type and may be tensorial. This development makes possible use of particle-based simulations in the homogenization and uncertainty quantification (UQ) of granular media. This is a significant development in the modeling of granular media, as it expands the role of particle-based methods for mesoscale simulations within a multiscale framework. The ultimate goal of this framework is to provide an additional path for constitutive characterization of particle aggregates, particularly in hydrocode modeling of high confinement, finite deformation phenomena. The power and versatility of the micro-mechanical boundary tracking algorithm is demonstrated through a series of numerical simulations of Eglin sand. The mesoscale models are used to compute the probability distribution functions of the moduli of Eglin sand at scales below the scale of the Representative Volume Element (RVE).