Modal analysis

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ShanJY
Posts: 4
Joined: Wed Nov 25, 2020 6:02 am

Modal analysis

Post by ShanJY » Thu Jan 07, 2021 6:30 am

Hello everyone:
When I perform a modal analysis of the structure, the eigenvalue results of the first few orders of modalities appear negative, so does anyone know where the error is. There is no error in the gravity analysis.
Thank you!

mhscott
Posts: 872
Joined: Tue Jul 06, 2004 3:38 pm
Location: Corvallis, Oregon USA
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Re: Modal analysis

Post by mhscott » Thu Jan 07, 2021 7:51 am

Your model is unstable somehow. Check the boundary conditions and apply other loads, not just gravity, to see if the analysis converges.

ShanJY
Posts: 4
Joined: Wed Nov 25, 2020 6:02 am

Re: Modal analysis

Post by ShanJY » Thu Jan 07, 2021 10:51 pm

Thanks for your help, I will make adjustments to my model based on your suggestions.

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