Participation factors after Modal Analysis

[meshparts]

Hello,

is there a possibility to get the participation factors of mode N after a modal analysis in all directions? I found something in the ansys help, by using

*GET, Par, MODE, N, PFACT

but only for ROTZ...

Why? How can I get it for UX for example? After a modal analysis, the output contains all mass participation factors for all 6 directions.

Thanks!

Alex

 

[Stringmaker]

Alex,
I'm out of the office so I cannot verify this but I think if you issue

OUTRES,ALL,ALL

before SOLVE this will output the information you desire. I'd recommend you verify this however.

Best,
-Brian

 

[Drej]

If you use:

*get,par,mode,n,pfact

this gives you the participation factor for mode n. If you square this value it will give you the effective mass for that mode, direction-independent.


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[cbrn]

Hi,
I'd suggest you redirect the output to file prior of doing the solution:
/OUITPUT,file,ext,

and then reset it to the Ouput Window afterwards:
/OUTPUT,,,

Regards

 

[meshparts]

Thanks cbrn and Brian!

With your help I know now a little bit more about modal mass and participation factors.

But I still have one problem: I wanted something like a *get function for automatically reading the modal mass for a specified DOF in to a variable. I need this for some user defined optimization routine.

Writing a program for getting the information from the output file would be too complicated if not impossible with APDL.

Interesting is that Ansys accepts one more keyword for the *get command

*GET, Par, MODE, N, PFACT

That's the DOF: UX, UY,... ROTZ

So I can input for example

*GET, Par, MODE, N, PFACT, UY

But I get always the same value. If I input a wrong keyword,

*GET, Par, MODE, N, PFACT, WrongKeyWord

then I get an Error Message. But not if I input UX, UY, UZ, ROTX, ROTY, ROTZ.

Is this a still not documented and still not working function of Ansys?

Regards,
Alex