Participation Factors, Modal masses etc.

A forum dedicated to feature requests and the future direction of OpenSees, i.e. what would you like, what do you need, what should we explore

Moderators: silvia, selimgunay, Moderators

Post Reply
divamva
Posts: 27
Joined: Wed Jun 30, 2004 6:52 am
Location: National Technical University of Athens

Participation Factors, Modal masses etc.

Post by divamva »

I believe it would be quite useful to have some way of getting out participation factors and modal masses. I have been thinking about trying some Modal Pushover Analysis and maybe some elastic response analysis and while these quantities are only a couple of matrix multiplications inside OpenSees they are very difficult to do using its output.
silvia
Posts: 3909
Joined: Tue Jan 11, 2005 7:44 am
Location: Degenkolb Engineers
Contact:

modal masses and participations

Post by silvia »

while I have to go back and review this topic, this is a very good suggestion!
what kind of data do you need to do this calculation? Is this something you can do in Tcl? the eigen command does give you eigenvalues, and I believe there is a way to get eigenvectors.
Silvia Mazzoni, PhD
Structural Consultant
Degenkolb Engineers
235 Montgomery Street, Suite 500
San Francisco, CA. 94104
divamva
Posts: 27
Joined: Wed Jun 30, 2004 6:52 am
Location: National Technical University of Athens

Post by divamva »

I am pretty sure that you only need the eigenvectors and the mass matrix

You can assemble the eigenvectors if you print out the model and I guess in the same way you could assemble the mass matrix and then do the necessary multiplications in Tcl. Still, it would be so much easier if it was done within Opensees where the mass matrix and the eigenvectors are already available.
janet986w
Posts: 1
Joined: Thu Sep 02, 2010 11:15 pm

Re: Participation Factors, Modal masses etc.

Post by janet986w »

[quote="divamva"]I believe it would be quite useful to have some way of getting out participation factors and modal masses. I have been thinking about trying some Modal Pushover Analysis and maybe some elastic response analysis and while these quantities are only a couple of matrix multiplications inside OpenSees they are very difficult to do using its output.[/quote]

I also think so.
:roll: :roll: :roll:

__________________
http://moviesonlineworld.com]
Post Reply