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PARAM, OMID and RMS Stresses

Pioneer
Pioneer

Hi

 

Could someone confirm that NX Nastran calculates the RMS stresses from a random analysis in the material coordinate system if PARAM,OMID,YES is set.

The documentation isn't very clear. FEMAP presents RMS stresses X & Y for plotting, but the NX Nastran documentation states the "xdb and op2 output do not change" if OMID is activated. So, are the RMS stresses X & Y available for plotting in FEMAP in the element coordinate system, or the material coordinate system?

 

The reason I ask, is using SAToolkit outputs the RMS stresses X & Y in element coordinate system even if PARAM,OMID,YES. So, I need to use Nastran output, but looking for confirmation.

 

I need RMS stresses in the material coordinate system.

 

Thanks

Peter

4 REPLIES

Re: PARAM, OMID and RMS Stresses

Siemens Phenom Siemens Phenom
Siemens Phenom

Yes, PARAM, OMID only affects printed output (.pch/.f06) for element force, stress, and strain results.

Re: PARAM, OMID and RMS Stresses

Pioneer
Pioneer

JimB

Are you confirming that the RMS X and Y stresses/strains are in the element coordinate system when FEMAP plots that RMS values, even when PARAM,OMID,YES is used in the analysis run?

PeterE

Re: PARAM, OMID and RMS Stresses

Siemens Phenom Siemens Phenom
Siemens Phenom

I confirmed what affect PARAM, OMID has on NX Nastran output.

 

I have no idea how FEMAP reads, interprets or presents data based on that output.

Re: PARAM, OMID and RMS Stresses

Siemens Phenom Siemens Phenom
Siemens Phenom

As stated above, PARAM,OMID only affects the f06 printout and the punch output. It does not change the op2(or xdb). Since Femap is normally reading the data from the op2, the value of PARAM,OMID does not have any effect on the data plotted in Femap, it is by default the element system regardless of the OMID setting.

 

Regards,

 

Joe