Create support structures in Netfabb and test their performance in Simulation Utility.
Video length (7:31).
Support structures are used to mitigate excessive distortion during powder bed processing. However, these structures are themselves subject to the same forces that distort the part. In this tutorial, a geometry with a large overhang area is modeled using homogenous support structures, with options enabled to check for support structure failure.
We will use Netfabb to create support structures for this part. Follow the step-by-step instructions shown in the video.
Sample files for use with the tutorials are available for download at https://www.autodesk.com/support/technical/article/caas/tsarticles/ts/2Yfrn77HGCZfr2IUaGPEJb.html. Expand the downloaded ZIP archive into a convenient directory from which you can import files into Simulation Utility LT as you need them.
You should see Generic MPBF selected at the top of the project model tree.
In the field to the right, set the distance to 0.00 mm and press Enter. The part must be seated directly on the platform for proper creation of support structures.
The lattice-like supports are created.
The exported file takes a minute or so to generate, then opens inside the Simulation Utility window.
One benefit of using Netfabb to generate supports appears here, in that the Volume Fraction is automatically calculated during support creation. Volume fraction is the amount of the support volume that is occupied by physical structures rather than empty space. Leave the existing value unchanged.
When the simulation finishes, the results appear.
You probably see several warnings of support structure failure. These indicate that the support structure failure criteria, specified in MPa units in the Solver Settings, was exceeded during simulation.
The Structure type results are color coded into 7 different element types, and the failed support structures are clearly visible in red.
For this example, you may want to turn the Element Edges back on in the Browser. The warped displacement results with visible element edges should look similar to the figure below:
Note that the elements at the support-part interface look distended. Rotate the part and zoom into the distended region.
Observe the excessive displacement of the part at this location. You may want to go back to the Mechanical log file and make note of one or more specific time increments when the warnings of support structure failure occurred. Use the Animation controls to go to a particular increment and see the state of the build at that time. For example, in the log file graphic shown above, you can see that increment 6 at 17668 seconds produced a warning.