Negative natural frequency.

[APH]

I'm doing frequency analysis on COSMOS and resulted in negative natural frequency. It ranges from -3400 Hz to 2700 hz in 13 modes. Something isn't right, but I'm not sure why.

any ideas?

Thanks
APH

 

[Tobalcane]

I don’t work with COSMOS, just curios what are the units of the X and Y axis that you are reading the profile off of?

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Tobalcane

 

[APH]

The unit is in Hz for frequency and modes. I'm not sure what happened there, but I simplyfied the model a little bit by getting rid of the small round and point and it cough up pretty good result, at least it makes sense.

APH

 

[Tobalcane]

Oh, you are reading it off a result window and not from a profile?

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Tobalcane