How to determine how many DOF a FE model has? 2

[Taz99]

Often you will see in articles the author stating that a FE model has xxx DOF to indicate how long it may take to run or to convey approximately how big the model is.
Could someone explain how I can get the number of DOF from either Patran or from Nastran output files?
Thanks

 

[rb1957]

dof = degrees of freedom ... = sum(n*d)
where n is a node, and d is the number of degrees of freedom at the node.

dof at a node can be fixed by the code (NASTRAN applied 6 dof at every node, those that aren't used are autospc'd)
or the code can assign dof depending on the element (a rod or a solid would have 3, a plate would have 6, a spring would have 1).

run statistics should tell you for a specific model.

 

[Taz99]

got it now - thanks!

 

[ZeroExperience]

To find DOF in MSC Nastran, I use the "estimate.exe" tool in C:\MSC.Software\MD_Nastran\20111\md20111\win64. I use the command prompt to run "estimate.exe" then I include the .bdf or .dat I wish to find the predicted resource requirements.

For example in the command prompt.

"estimate.exe model.bdf"