Discrete element method to simulate continuous material by using the cohesive beam model

Abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. AbstractThe mechanical behavior of materials is usually simulated by the continuous mechanics approach. However, simulation of non-continuous phenomena like multi-fracturing is not well adapted to a continuous description. In this case, the discrete element method (DEM) is a good alternative because it naturally takes into account discontinuities.Many researchers have shown interest in this approach for wear and fracture simulation. The problem is that, while DEM is well adapted to simulate discontinuities, it is not suitable to simulate continuous behavior. In problems of wear or fracture, material is composed of continuous parts and discontinuous interfaces. The aim of the present work is to improve the ability of DEM to simulate the continuous part of the material using cohesive bond model.Continuous mechanics laws cannot be used directly within a DEM formulation. A second difficulty is that the volume between the discrete elements creates an artificial void inside the material. This paper proposes a methodology that tackles these theoretical difficulties and simulates, using a discrete element model, any material defined by a Young's modulus, Poisson's ratio and density, to fit the static and dynamic mechanical behavior of the material. The chosen cohesive beam model is shown to be robust concerning the influence of the discrete element sizes. This method is applied to a material which can be considered as perfectly elastic: fused silica.

A bond model for DEM simulation of cementitious materials and deformable structures

“…The manner in which the developed model uses breakable beams to connect an assembly of DEM particles is similar to those employed by other authors [e.g. 12,25].…”

“…Most of the work has covered the behaviour of cementitious materials under quasi-static uni-axial loading, such as rock in 2D [8] and 3D [6,7], and concrete in 2D [18] and 3D [12]. A uni-axial loading test is often used to calibrate models for different materials.…”

“…[11][12][13][14]. The contact laws can be based on Euler-Bernoulli or Timoshenko beam theory, and the elements are able to resist tensile force and bending and twisting moments.…”

Using the discrete element method to simulate brittle fracture in the indentation of a silica glass with a blunt indenter

“…The failure criterion σ hyd f was calibrated using the same procedure described for the microscopic elastic parameters in (6). A series of failure tensile tests was Figure 8 shows the evolution of the macroscopic failure stress for different values of the microscopic failure criterion.…”

“…The first step of simulating the elastic behavior of silica (as represented by the Young's modulus and Poisson's ratio), was achieved using the cohesive beam bond model. This method was detailed in a previous paper (6).…”