Virial stress–based model to simulate the silica glass densification with the discrete element method

Abstract

International audienceThe discrete element method (DEM) presents an alternative way to model complex mechanical problems of silica glass, such as brittle fracture. Since discontinuities are naturally considered by DEM, no complex transition procedure from continuum phase to discontinuum one is required. However, to ensure that DEM can properly reproduce the silica glass cracking mechanisms, it is necessary to correctly model the different features characterizing its mechanical behavior before fracture. Particularly, it is necessary to correctly model the densification process of this material, which is known to strongly influence the fracture mechanisms. The present paper proposes a new and very promising way to model such process, which is assumed to occur only under hydrostatic pressure. An accurate predictive-corrective densification model is developed. This model shows a great flexibility to reproduce extremely complex densification features. Furthermore, it involves only one calibration parameter, which makes it very easy to apply. This new model represents a major step towards accurate modeling of materials permanent deformation with the discrete element method, which has long been a huge challenge in applying this method for continuum problems

A discrete element framework for the numerical analysis of particle bed-based additive manufacturing processes

“…structured lattices, but performs adequately in most DEM simulations [36,[46][47][48][49]. The stress tensor of a selected volume V is computed, summing over all interaction pairs N p in its domain, according to the following equation:…”

Analytic laws for direct calibration of discrete element modeling of brittle elastic media using cohesive beam model

“…In this study, a fracture criterion, based on the computation of an equivalent Cauchy stress tensor (the so-called virial stress tensor) and maximal principal stress value, is involved. Several researches pointed out that virial stress-based model seems to be suitable for simulating elastic brittle material [4,14,24]. Mainly, virial stress tensors are used as post-processing tool for computing stress maps in a DEM calculation.…”