Fusion 360 Simulation: View TET Element with Singular Geometry

[Anonymous]

I am running a simulation on a complex imported part with a lot of surfacing issues in the original file. I have successfully been able to refine the model to achieve a mesh and run a simulation. In the Solver Data, however, I see numerous "Warning: TET ELEMENT ____ HAS SINGULAR GEOMETRY". 

Is there a way to have Fusion highlight which elements these are, similar to what is shown when a mesh fails to generate? I would like to be able to check whether these singularities are critical and where they are in the model. 

Thank you, 

[John_Holtz]

Hi @Anonymous 

Fusion does not have any mechanism to show particular elements.

Even it you could see which elements are causing the singularity warning, you would not be able to use that information to know if the results are correct or not. A singular element is putting some bad stiffness numbers into the matrix of equations that is being solved. How that propagates through the solution and affects the results would be impossible to predict.

If your model has curved geometry, especially with very small curvature, my suggestion would be to turn the "Manage > Settings > Mesh > Advanced Settings > Create Curved Mesh Elements" off (uncheck). That could be causing distorted elements similar to this article: A nonlinear analysis fails to converge in Autodesk Nastran. (I see the stupid web formats have made the image in that article unusable. The full size image is below.) If you still received singularity warnings with curved elements unchecked, then a finer mesh (smaller mesh size) should improve the element shape. (There may be very thin faces or pointy corners that are causing long skinny elements in the model. If you could find and eliminate those, that would be helpful.)

Element highlighted in Nastran In-CAD/Inventor Nastran.

Let us know if you can eliminate the singularity warnings.

[John_Holtz]

Hi @Anonymous 

I wanted to follow-up with you to ask if you have any questions.