Simulation and Analysis of the Uniaxial Compression test
This section provides instructions for running a uniaxial compression test simulation in EDEM and post-processing the results using the files provided. The Freeman Uniaxial Powder Tester (UPT) was chosen as a case study.
Introduction
During the test, a powder sample confined in a rigid cylinder undergoes uniaxial compression under a known vertical stress and is subsequently crushed in the unconfined state as shown in Figure 1. The physical responses of interest are the initial packing state, the stress-strain response during confined compression, and unconfined compression strength.

Prerequisites
The simulation and analysis procedure described in this section requires EDEM version 2022 or later. The Calibration Kit examples are installed in the . Copy the Calibration kit and examples to a processing folder before they are configured and run.
The analysis described in this section uses EDEMpy. For more information about EDEMpy, see the EDEM Help documents.
Running Simulations
- Run the simulation till the end.The stages of the test described in Figure 1 are modeled using EDEM kinematics controllers as shown in Figure 2.
Figure 2. Uniaxial compression test piston kinematics
Uniaxial compression tests produce measurements in the quasi-static flow regime where the macro-mechanical behavior of granular materials is independent of the strain rate . Therefore, the compression rate in the provided EDEM deck is accelerated to leverage computational efficiency. If the particle properties or the applied normal stresses in the model change significantly, the compression rate may need to be adjusted to ensure the quasi-static flow regime is maintained. This can be achieved by changing the piston vertical velocity as shown in Figure 2.
Automatic post-processing of results with EDEMpy
You can calculate the physical responses of interest in the uniaxial compression test
from the EDEM simulation data using the
UCT_analyst_v3.py
script provided.
UCT_analyst_settings.txt
file, as shown in Figure 3.

- Arrange the files as shown in Figure 4.
- Open a blank or existing EDEM simulation file, and go to .
- Go to
UCT_analyst_v3.py
script.Reports and graphs will be generated in the master folder. Individual reports will contain all the relevant data and the summary report will contain only time-averaged results.
Only complete simulations with the corresponding settings files will be post-processed. Otherwise the script will produce error messages as shown in Figure 5, and then move to the next simulation in the folder tree.Note: All simulation files must have unique folder names and simulation names. If the simulation names are identical, the results report will be overwritten.Figure 5. Possible error messages
and then select the
Script Version changes
Version 3 of the UCT analyst script is designed to work with EDEM version 2022.0 (and later) and EDEMpy. This EDEMpy version
includes a change where creatordata
is indexable, and all
references to creatordata
have been replaced with
creatordata[0]
.