×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

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

How to determine how many DOF a FE model has?

How to determine how many DOF a FE model has?

(OP)
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 :)

RE: How to determine how many DOF a FE model has?

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.

RE: How to determine how many DOF a FE model has?

(OP)
got it now - thanks!

RE: How to determine how many DOF a FE model has?

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"

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources