OpenSees 2.5

Forum for OpenSees users to post questions, comments, etc. on the use of the OpenSees interpreter, OpenSees.exe

Moderators: silvia, selimgunay, Moderators

Post Reply
mohammadjjj
Posts: 7
Joined: Mon Feb 01, 2016 5:00 pm

OpenSees 2.5

Post by mohammadjjj »

Dear Users
I'm searching about MODAL DAMPING Command in Opensees (or applying Modal Damping) in Opensees
Would you please help me ? Pleaseeee
fmk
Site Admin
Posts: 5884
Joined: Fri Jun 11, 2004 2:33 pm
Location: UC Berkeley
Contact:

Re: OpenSees 2.5

Post by fmk »

there are 2 commands:
modalDamping $ratio
modalDampngQ $ratio

the latter ignores adding any part of C to the tangent matrix. the commmand uses the existing eigenvectors, so the eigenvector command must have been issued first. a wipe currently does not remove the factor, so if in a script you want to play with modal and then rayleigh you need to call the modal command with a 0 ratio before the analyze. you can issue a rayleigh command with he modal to damp out high frequency modes that are not covered as Prof. Powell recomends in the PERFORM manual. The issue never popped up (in the responses i have looked at) so don't know how much of an issue it is as at least for the disp response the response is governed by the fundamental modes.
Farid
Posts: 23
Joined: Thu May 05, 2005 11:10 am
Location: University of California, Los Angeles

Re: OpenSees 2.5

Post by Farid »

Hello Frank,

Does modalDamping work with domain decomposition?
Post Reply