frequency peaks in modal frequency response
frequency peaks in modal frequency response
(OP)
Hi,
doing a frequency response, I requested the output to be calculated also at the eigenfrequency of my structure by mean of a FREQ3 card.
Looking at the results, I noticed that the eigenfrequencies reported were slightly different that those I could calculate directly from a modal analysis.
Could someone explain? Is this a matter of accuracy?
I thought that it should be the same since the NASTRAN method is based on a modal frequency response. Could the residual vectors improve the results?
Thanks in advance for your answers.





RE: frequency peaks in modal frequency response
Brian
www.espcomposites.com
RE: frequency peaks in modal frequency response
sorry for the late answer but I was out of this office for some weeks. Thanks for the answer, I will look at it. This could be an explaination.
Cheers.
RE: frequency peaks in modal frequency response
Brian
www.espcomposites.com
RE: frequency peaks in modal frequency response
If yes, then the eigenfrequency will differ. Becasue they don't have any influence in Modal Analysis.