Post-Process the Results

1. After the solution is completed, the results are automatically loaded into Autodesk Nastran In-CAD.

   

2. You can see in the tree view that results have been calculated for the initial stress and the buckling subcases, and both are loaded in Results.
3. Autodesk Nastran (the solver) calculates the displacements to graphically represent the modal shapes for each eigenvalue extracted.
4. Double-click on Results and select Mode 1, EIGV= 1315.821 from the Subcases list.
5. Check Deform Options and click on Display. The plot should look as shown below.

   

   

6. The first and lowest eigenvalue is about 1316, which is of primary interest.
7. When multiplied by the applied load, 1Psi, you get the lowest critical buckling load of ~1316Psi.

This concludes Linear Buckling Analysis of a Dome Lid.

The following summarizes the main topics covered:

• How to set up a simple linear buckling analysis.
• How to interpret the eigenvalue extraction results.
• How to calculate the lowest critical buckling load.