How to determine the number of degrees of freedom in a Simcenter Nastran analysis?

2022-09-20T17:13:12.000-0400

Summary

Sometimes it's important to know the number of degrees of freedom i.e. DOF in an analysis. This FAQ explains how to do so.


Details

The solution of the system of equations is usually the most computationally intensive part of an analysis.

Information about the solution is contained in the .F04 file.

An example is as follows:

 *** USER INFORMATION MESSAGE 4157 (DFMSYN)
     PARAMETERS FOR SPARSE DECOMPOSITION OF DATA BLOCK  KLL     ( TYPE=RDP ) FOLLOW
                      MATRIX SIZE =       12 ROWS

So the number of degrees of freedom is 12.

It's noted that this is different than the information in the .log file as follows:

Finite element model generated 48 degrees of freedom.

The above is for a simple model of one brick/hexahedral element without mid-side notes with one face i.e. four nodes fixed in all three directions.

KB Article ID# KB000065611_EN_US

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