Periods and modes for 3 story frame

HBP · Post by **HBP** » Mon Aug 07, 2006 5:38 pm

Hi,

I would really appreciate if you could help me find the reason why I cant find the periods accurately for a 3-story frame using OpenSees.

First, I did the modal analysis using OpenSees. Then I obtained some valued for Periods and modes.

After that, I used an alternative procedure for obtaining the same values. This procedure starts by obtaining the condensed stiffness matrix of the structure, using the flexibility method (lateral forces = 1 at DOFS). Then, as I have the stiffness and mass matrices, I can get the modes and periods (Matlab file).

I'm sending an email to your address (opensees-support@berkeley.edu), with the files that I used for the procedure explained above.
I really appreciate your help.

Thanks,

Hugo Bobadilla
Grad student UC Berkeley