Introduction
I have been using and supporting the Altair Radioss™ explicit FE solver for over a year now, and the whole PolyUMod® library is available for Radioss. So it was quite exciting when I recently learned that the Radioss FE solver has been open sourced, and is now part of the community-based OpenRadioss initiative. You can now download the complete source tree from github! This is an excellent opportunity for anyone who is either interested in learning how a commercial-quality explicit FE solver works, or just wants to use a good explicit FE solver for free. This article describes how you can download, compile, and run a simple test case using OpenRadioss.
It is all really easy. Read on for the details!
Download and Compile OpenRadioss
I am going to demonstrate how to download, install, and use OpenRadioss using a Linux computer running Ubuntu 22.04 or RedHat 8. The first step is to open a terminal and go to a suitable target directory. Make sure you have git lfs installed, using something like sudo yum install git-lfs. Then type the following command to download the source file repository:
git clone https://github.com/OpenRadioss/OpenRadioss.git
Altair Radioss consists of two executable files called starter and engine. The starter processes the input file, and the engine runs the FE calculations.
The next step is to compile the starter:
cd OpenRadioss
cd starter
./build_script.sh -arch=linux64_gf
This command takes a few minutes to run. The next step is to compile the engine:
cd ../engine
./build_script.sh -arch=linux64_gf
Once this finishes you should have the two execuables starter_linux64_gf and engine_linux64.gf in the directory ../exec.
Run an OpenRadioss Test Case
Note that OpenRadioss comes with multiple exemplar test cases. To test the newly compiled version of OpenRadioss I wanted to run my own test case.
My test case consists of a cylinder undergoing simple shear. The figure to the right shows the deformed mesh plotted using Hypermesh. You can download my test case from here:
I think that the easiest way to run the test case is to launch it from a bash file. Here is the file that I used:
Once I run this script file the simulation just runs to completion, and generates many results files along the way. The easiest way to view the results that I have found is to use Altair Hyperworks.
That is all there is to it. You now have access to a powerful explicit FE solver, and you can play around with it in any way you like.
I am very curious to see how this FE tool will evolve now that it has been open sourced
#!/usr/bin/bash
set -e
rhome="/home/jorgen/FEA/OpenRadioss"
export LD_LIBRARY_PATH=".:$rhome/extlib/hm_reader/linux64"
export RAD_CFG_PATH="$rhome/hm_cfg_files"
export RAD_USERLIB_LIBPATH=/opt/PolymerFEM/PolyUMod/PolyUMod_RADIOSS
echo ** Run Starter **
$rhome/exec/starter_linux64_gf -i cylinder_shear_BB_0000.rad
echo ** Run Engine **
$rhome/exec/engine_linux64_gf -i cylinder_shear_BB_0001.rad
echo Done
