Breakage of flawed particles by peridynamic simulations

Abstract

In this paper, we use a 2D bond-based peridynamic model to investigate the strength of disk-shaped particles including pre-cracks. We use a diametral (or Brazilian) test to break the particles. For the flawless particles, we find that the stress distribution compares well with an analytical model accounting for the size of the contact zone, and the particle stiffness tends linearly to a well-defined value for increasingly resolved meshing. We then introduce cracks, which are numerically defined by reducing the Young modulus of the bonds crossing linear segments. We consider in detail the effect of a single vertical crack on the yield stress as a function of its position. We also consider a randomly distributed population of cracks with sizes generated from a Gaussian size distribution. For a parametric study with a hundred particles, we found a probability of failure that is well fit by a Weibull law. Finally, using an image analysis algorithm, we investigate the statistics of cracks and the resulting fragments.

Fine comminution of torrefied wheat straw for energy applications: properties of the powder and energy balances of the production route

“…However, obtaining powder of this order of magnitude requires the plant material to be fractionated below the cellular scale (<50 microns) which poses challenges in terms of energy requirement. Indeed, comminution results from fractures which are initiated and propagated mainly through defect zones 9 naturally present in the structure of the plant. These zones are much more numerous at the plant tissue level than at the cellular scale.…”

Study and Modeling of the Grinding Kinetics of Reactive Rocks in a Cement Laboratory

“…Some authors report that the agglomeration of fine particles, due to van der Waals or electrostatic forces [13] [14] [15] [16] [17], leads to the decrease of the specific surface and consequently the increase of the energy consumption and the modification of the product properties. Blanc et al [18] analyzed the long-term grinding of silica sand in an oscillating ball mill. They highlighted the correlation between the agglomeration of fine particles and the volume fraction of the finest ones, which influences the specific surface as a function of grinding time.…”