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Freebody tool in Frequency response analysis

Experimenter
Experimenter

Hello,

I am working on a structure consisting of beam like members, I have performed fully mapped mesh with Solid HEX elements. I want to extract NQM forces at some planes across the length of the beams. To do this, I used the freebody tool which works really well in a linear static analysis (SOL101). However, when I perform a frequency response analysis (SOL108) the freebody tool doesn't work anymore. On the Nastran Output Requests, I request Nodal force balance outputs to get the nodal forces data. Does the freebody tool work on frequency response analysis? Is there any other way to extract the NQM forces from the Solid elements?

 

Regards,

Dimitris.

6 REPLIES 6

Re: Freebody tool in Frequency response analysis

Experimenter
Experimenter
Is there any solution to this problem? Any help would be really appreciated.
Dimitris.

Re: Freebody tool in Frequency response analysis

Siemens Phenom Siemens Phenom
Siemens Phenom

What version of Femap/Nastran are you using? Can you post the case control section of the .dat file that was written?

Re: Freebody tool in Frequency response analysis

Solution Partner Creator Solution Partner Creator
Solution Partner Creator

There is a “trick” to getting this to work.  You need to have PARAM,DDRMM,-1 in your Nastran input file.

 

To do this in FEMAP, enable the “DDRMM off” option in the NASTRAN Bulk Data Options dialog box:

 

2019-04-16_11-21-56.png

 

From the NX Nastran Quick Reference Guide entry for “GPFORCE” in the Case Control section:

 

Remark 3. PARAM,DDRMM,-1 is required in the modal solution sequences 111, 112, 146, and 200.

Re: Freebody tool in Frequency response analysis

Experimenter
Experimenter

I use Femap V11.2.2 with NX Nastran 10. I uploaded the .dat file of a test model.

I tried ticking the DDRMM off option but still no difference neither with SOL108 nor with SOL111 solver. When I try simple static analysis, I am able to use the freebody tool.

Re: Freebody tool in Frequency response analysis

Siemens Legend Siemens Legend
Siemens Legend
 

Re: Freebody tool in Frequency response analysis

Siemens Phenom Siemens Phenom
Siemens Phenom

Currently, the Femap freebody tool does not support complex result vectors.

 

Regards,

 

Joe