Simulation and Analysis of the Inclined Plate test

This section provides instructions for running an Inclined Plate Test (IPT) in EDEM and post-processing the results using the files provided.

The test consists of consolidating a bulk solid sample on a flat plate under a specified weight and then rotating the plate at a constant rotational velocity until the sample slides off as shown in Figure 1. The angle at which the unconfined sample begins to slip, termed as 'initial slip angle', and the angle at which all of the material is sliding on the wall, termed as the 'final slip angle', are used to characterize the bulk solid-equipment interaction for cohesive solids. These measurements are suitable to use as a benchmark for the calibration of Particle-Geometry interaction in EDEM simulations for cohesive bulk solids.



Figure 1. DEM simulation of the Inclined Plate Test

Prerequisites

The simulation and analysis procedure described in this section requires EDEM version 2022 or later. The Calibration Kit examples are installed in the Altair installation folder > EDEM (version) > examples > Calibration Kits. 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

An example EDEM deck for the inclined plate test is provided, but this procedure can be applied to tests with different dimensions. You can run the simulations directly in EDEM. Run the deck provided in EDEM and do the following:
  1. Run the simulation till the end.
    The consolidation stage of the test shown in Figure 1 is modeled using EDEM kinematics controllers as shown in Figure 2. You can modify the applied stress by changing the vertical force magnitude in the controller.


    Figure 2. Consolidation stage kinematics

The plate rotation is modeled using a constant rotational velocity kinematic as shown in Figure 3. The physical test is performed at a low rotational velocity of 2-3 deg/s to avoid inertial effects on the results. It is recommended to adopt a similar approach in the EDEM simulations.



Figure 3. Plate rotation kinematics

Post-processing results automatically with EDEMpy

You can automatically calculate the initial and final slip angles in the IPT test from the EDEM simulation data using the IPT_analyst_v3.py provided. The post-processing script utilizes the EDEMpy library to locate all EDEM decks in the folder containing the script and subfolders. Finally, it generates reports and figures with all the relevant data. The analysis settings for the script are defined in the UCT_analyst_settings.txt file, as shown in Figure 3.

The analysis settings for the script are defined in the IPT_analyst_settings.txt file, as shown in Figure 4. The determination of the initial and final slip angles is done on the basis of the degree of Particle-Geometry friction mobilization quantified by the percentage of particle in contact with the sliding plates. Reasonable values for the initial and final slip thresholds are 75% and 95% respectively. In cases when a significant amount of material adheres permanently to the plate, the final slip threshold may need to be decreased or ignored.


Figure 4. Contents of the IPT Analyst Preference file

You can post-process multiple simulation decks with the script by arranging the files into one of the two configurations as shown in Figure 4. The second configuration is recommended, as it allows for individual settings files for each EDEM deck, and therefore post-processing of different types of tests can be done simultaneously. In the first configuration, a single settings file is read for post-processing all decks.



Figure 5. File configuration for post-processing multiple simulations
To run the IPT_analyst_v3.py script:
  1. Arrange the files as shown in Figure 5.
  2. Open a blank or existing EDEM simulation file, and go to EDEM Analyst > Run > EDEMpy Script.
  3. Go to Select File > Run Script and then select the IPT_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.
    Note: Only complete simulations with corresponding settings files will be post-processed. Otherwise the script will produce error messages as shown in Figure 6 and move to the next simulation in the folder tree.


    Figure 6. Possible error messages

In order for the script to function properly, the name of the equipment material used to model the plate must be the same as the name set in the deck provided.

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].