On the validation of DEM and FEM/DEM models in 2D and 3D

Abstract

PurposeAs particulate systems evolve, sliding, rolling and collision contacts all produce forces that discrete element method (DEM) methods aim to predict. Verification of friction rarely takes high priority in validation studies even though friction plays a very important role in applications and in mathematical models for numerical simulation. The purpose of this paper is to address sliding friction in finite element method (FEM)/DEM and rolling friction in DEM.Design/methodology/approachAnalytical solutions for “block sliding” were used to verify the authors' tangential contact force implementation of 2D FEM/DEM. Inspired by the kinetic art work Liquid Reflections by Liliane Lijn, which consists of free balls responding within a rotating shallow dish, DEM was used to simulate rolling, sliding and state‐of‐rest of spherical particles relative to horizontal and inclined, concave and flat spinning platforms. Various material properties, initial and boundary conditions are set which produce different trajectory regimes.FindingsSimulation output is found to be in excellent agreement when compared with experimental results and analytical solutions.Originality/valueThe more widespread use of analytically solvable benchmark tests for DEM and FEM/DEM codes is recommended.

Analiza stabilnosti suho zidanih kamenih nadvoja kombiniranom metodom konačno-diskretnih elemenata

“…gdje je f t tangencijalna elastična kontaktna sila, k t je penalty koeficijent za trenje, a d t je tangencijalni vektor pomaka između dva elementa [22]. Ako je f t veća od maksimalne sile trenja koja je definirana Coulombovim zakonom, | f t |>µ| f n |, tada elementi klize jedan duž drugog, a posmična je sila između njih definirana preko elastične normalne sile f n prema…”

Application of the finite-discrete element method to dynamic stress development in armour units and armour layers

“…Such FEMDEM approaches have been successfully applied to modelling the key processes of stress wave propagation and expanding gas-driven fragmentation in Rock Blasting (Munjiza et al 2000). Recently, Coulomb friction was also implemented in 2D by Xiang and Guises (Xiang et al 2009b). The FEMDEM method has already proven its efficiency and reliability as a computational tool to solve problems involving simulations with motion and collisional dynamics of systems in which deformation and fracturing play an important role.…”

A combined finite–discrete numerical model for analysis of masonry structures

“…Material non-linearity including fracture and fragmentation of discrete elements is considered through contact elements [19] which are implemented within a finite element mesh. The interaction between discrete elements is considered through the contact interaction algorithm based on the principle of potential contact forces [20] and the Coulomb-type law for friction [21]. The method uses an explicit numerical integration of the equation of motion.…”