"FATAL ERROR S1117: INTERNAL ERROR DETECTED IN MODULE" in Nastran analysis (mesh issue)

Autodesk Support

Oct 23, 2024

Products and versions covered

Issue:

When attempting to run the model with a fine mesh in Nastran In-CAD, it generates the following error (shown in the log file): 
FATAL ERROR S1117: INTERNAL ERROR DETECTED IN MODULE

 

Causes:

This is caused by highly distorted elements in the model.

Solution:

Press-Fit or Shrink Fit Analysis

In a press-fit analysis, significantly differing mesh density can cause this error.  Ensure that all contacting surfaces in regards to the interference have the same mesh density.
 

Problem with Mesh

Highly distorted elements in the model can cause this problem. There are two ways to locate the distorted elements:

  1. Check the Mesh Quality. Look for elements that either have a small positive, negative, or INF values reported for Jacobian. See below for details.
  2. Check the log file for G3005 warnings. See below for details.

After locating the problematic area, resolve or simplify the geometry near the failed element.

  • For example, if the problem is near a small feature such as a chamfer or fillet, suppress the feature in the Inventor modeling environment.
  • If the model is an imported CAD, use Inventor's Repair Bodies to identify and possible fix the model. ("3D Model > Surface > Repair Bodies")
  • Change the mesh size slightly.

Check the Mesh Quality

  1. Right click on "Mesh Model" in the Model Tree and select "Check for Mesh Quality".
  2. In the Mesh Quality window, set the desired parameters. For example, set the Jacobian value to 0.01 to find problematic elements.
  3. Click "Check". This shows a new dialog with a list of elements that fail the quality tests.
  4. Click a column header to sort the table based on the value. For example, click the Jabobian column to sort in ascending or descending order.
  5. Click Highlight in the Failed Elements window.
  6. The failed elements should now be highlighted in green.

See How to understand geometry warnings (G30xx) in Nastran analysis for additional tips on using the Check Quality for Mesh.


Check the Log File

See How to resolve Warning G3005 Grids Collocated On Tet Element in Nastran.

 

Products:

Inventor Nastran;

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