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Nastran RESVEC card usage in rotordynamics analysis

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Dav3dum

Mechanical
Mar 27, 2018
6
Dear All,

I have question regarding the RESVEC card in NX nastran.
This card is used by default in frequency response calculations (SOL111) to expand modal model to get more accurate results. My question is basically pertaining to the usage in rotordynamics analysis. The user guide explicitly states that in case of rotordynamics analysis the residual vectors shall not be used, yet the program doesn't throw an error if you define it, and also it has an effect on the Campbell diagram as well. So can we use that card in rotordynamics analysis, and if no why not?

Also what about frequency response calculations where there are rotordynamics effects as well, shall it be turned off there as well?

If I get it right the residual vector uses static loads to expand the modal model. If it's the case then how does the software formulate the residual vectors when there is no load present in the simulation ( basic SOL110 calculation)?

Thanks in advance
 
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