eigenvectors are 0

bufa · Post by **bufa** » Tue Jul 05, 2005 5:44 am

Hi,
I work on a simple rc frame, imposing displacements with different multipleSupport load pattern to the nodes of it.
Now, if I do an eigen analysis I can have eigenvalues, but eigenvectors are 0, I think because nodes are not considered free, but fixed. Is it correct? How can I solve this problem?
Thanks

Post by **fmk** » Tue Jul 05, 2005 10:14 am

you will have to look at the eigenvalues without the multi-support motion .. these introduce single point constraints which are causing the 0's.

bufa · Post by **bufa** » Tue Jul 05, 2005 11:37 pm

thanks fmk, but I need eigenvalues and eigenvecors of the deformed structure. Isn't possible to have them?

Post by **fmk** » Wed Jul 06, 2005 10:14 am

after the analysis is completed just remove the load pattern and then do the eigen analysis.

silvia · Post by **silvia** » Sat Jul 16, 2005 10:53 pm

interesting.
would you, the OP, please post an example once you have done this? i would love to add it to the documentation.
tia!!