Automating EDEM and OptiStruct Integration with Altair Pulse

Introduction

In advanced engineering simulations, the Discrete Element Method (DEM) and Finite Element Analysis (FEA) are two important methods for understanding and predicting the behavior of materials and structures under various conditions. For bulk materials, simulations are often done using DEM software like Altair® EDEM™, in which the interaction of the bulk material and the system can be predicted. On the other hand, FEA software like Altair® OptiStruct® can be used to understand how structures will respond when under stress. Usually, the process of exporting EDEM results and importing them in OptiStruct is a very manual and time-consuming process. However, with Altair® Pulse™, it is possible to automate this workflow, making it faster, more accurate and more efficient. In this blog post, you’ll get an overview of a workflow that integrates EDEM and OptiStruct using Pulse.

Why Automate the EDEM to OptiStruct Workflow with Pulse?

The process of manually extracting and processing EDEM results before analyzing them in OptiStruct can take a lot of time if there are many timesteps in the EDEM simulation as it involves a lot of clicking, which makes it very prone to errors. By creating a Pulse workflow to automate this entire process, not only can we save time as the workflow eliminates all manual steps of the process besides being highly reusable, but we also ensure that no mistakes were made along the way, which makes our analysis more reliable.

Files

All simulation files can be downloaded here.

Software Requirements

It is recommended to use the 2023.1 version of all the software to ensure compatibility with the shared files.

Workflow Overview

To use the workflow, you first need a completed EDEM simulation and .hm file with the appropriate boundary conditions defined. In the attached files you’ll find one EDEM simulation of the loading and unloading process of a dump truck (unsolved), shown in Figure 1, and the corresponding .hm file of the truck body with one single point constraint already defined.

Figure 1: Simulation of loading and unloading a dump truck using EDEM

Step 1  – Changing the use profile and adding the files to your library

After unzipping the attached files, open Pulse then click on File > Preferences. Click on Generic and in User Profile select Orchestrator. You can learn more about the different Pulse user profiles in this blogpost. Next, click on Library and select the Pulse_Library folder. Finally, click on Apply and OK.

Step 2 – Create the Workflow

Once all files have been added to Pulse, click on View and make sure that Library Browser is checked. On the right, in the Library Browser, expand the EDEM, Solvers and Visualization folders. Drag and drop the EDEM2HM, FieldLinearStatic, OptiStruct and OpenH3D modules into the Block Diagram window. If an Application Mapping window shows up, just click OK. Finally, connect the blocks as shown in Figure 2. Once two modules are connected, the output of the first is used as input for the second.

Figure 2: Connected blocks in Pulse

Step 3 – Define the inputs

After all modules have been connected, it is time to define the inputs, starting with the EDEM2HM module. By right clicking on the EDEM2HM module then clicking on Edit Input a new window will show. In this window, you have to specify the EDEM deck (.dem file), the geometry name and the start and end time, in seconds, for your analysis. The EDEM2HM module will then create, for each timestep in the defined range, a csv file containing all forces acting on the specified geometry.

Figure 3: EDEM2HM module input parameters

Next, we have to define the inputs of the FieldLinearStatic module. For this module the parameters are HyperMesh file with boundary conditions defined, the search radius, in meters, that will be used to map the forces to the geometry nodes and the geometry name. Please note that, to be compatible with the results of the EDEM2HM module, the HyperMesh file must be created using SI units.

Finally, no additional inputs are required since the OptiStruct and OpenH3D modules are already connected to other modules.

Figure 4: FieldLinearStatic module input parameters

Step 4 – Run the Workflow

Once all inputs have been defined, we can run the workflow by clicking on the Run button on the Execute tab. After saving the project, Pulse will start running the workflow and all modules will be executed automatically and sequentially. While a module is running it’ll show a loading icon next to its name. Once a module’s finished that icon will change to a check mark and Pulse will move on to the next module. Keep in mind that the time it will take to complete the workflow depends on the number of csv files created by the EDEM2HM module. On average, it takes approximately 30 seconds for the FieldLinearStatic module to process each csv.

Once the FieldLinearStatic module has finished running and before the OptiStruct blocks begins, a window will show up. Just click on Proceed so that block starts. After the OptiStruct analysis is done, a HyperView window will show up and we are able to visualize our results.

Figure 5: Side-by-side EDEM and OptiStruct results

Conclusion

The objective of this example is to demonstrate how Pulse can integrate, automate and streamline the process of exporting EDEM results to be analyzed in OptiStruct. This saves on setup time, cutting out manual, click-intensive tasks and avoids the possibility of making manual mistakes.

This EDEM-Pulse workflow can be applied to other applications where a repetitive task can be automated.