# discrete element method

## Compiling C++14 code on a cluster with clang

For those of you who have to port codes to supercomputers:

New article: Compling C++14 code on a cluster.  http://www.parresianz.com/dem/compiling-paraellip3d-for-a-cluster/

-- Biswajit

## DEM Open Forum and ESyS-Particle Workshop

DEM Open Forum and ESyS-Particle Workshop

University of Glasgow

Wed., 30/08/2017, 8:30 am – Fri., 01/09/2017, 5:00 pm

## Impact Force plotting using Abaqus/Explicit

Hello Everyone

I am trying to simulate material dumping process from shovel onto mining dump truck. And for that i am using Abaqus/Explicit.  When i plot the contact force of material falling onto truck body under gravity, it gives me the maximum value of 0.12e+11, where as a simple theoretical analysis shows that the resulting impact force for 100 tons of material falling under gravity should be 9e5 N. I am not been able to understand the reason that why Abaqus /Explicit is exaggerating the impact/contact force so much. And i dont know how to correct this thing.

## Shape of particles in DEM

Many granular materials encountered in engineering practice are of irregular shapes that are not essentially smooth or rounded. However, in DEM, grains are idealized as spheres and ellipsoids and their surface are assumed to be sufficiently smooth. As a result, I wonder why there is no model of  irregular shapes and what is the difficulty on implementing such a model? Is there any recent work aimed to simulate grains of irregular shape? Thanks a lot.

## the DEM's solutions for static mechanics seem strange

My own DEM(Discrete Element Method) program's solution for static problem seems strange.

I use my program to calculate the displacement of a cantilever under static pressure:

1. it seems my program shows convergence for static problem as the mesh gets denser. As the mesh grows denser(that means the particle becomes smaller), the displacement(of y direction)  of the free tip becomes smaller.